What is a hundred, an are, a hectare, a square kilometer? How many hectares? square meters and kilometers in one are (area) of land? How many square meters, kilometers and acres are in one hectare of land? How many acres, hectares and square meters are in one square kilometer?

How many square meters in 1, 10, 100, 1000 acres: table

What is one hundred square meters of land? A hundred square meters of land is a unit of measurement for the size of a plot; a hundred square meters is equal to one hundred square meters.

To measure areas, the following units are used: square millimeter (mm 2), square centimeter(cm 2), square decimeter (dm 2), square meter (m 2) and square kilometer (km 2).
For example, a square meter is the area of ​​a square with a side of 1 m, and a square millimeter is the area of ​​a square with a side of 1 mm.

You can also say that there are 100 square meters in one hundred square meters. meters and it would be correct if we say in hectares that one hundredth of a hectare is one hundredth of a hectare.

• A weave is a unit of measurement for the size of a plot, which is often used in dacha or agriculture. In science, it is customary to use an analogue of weaving - ar. Ar (one hundred square meters) is the area of ​​a square with a side of 10 m.
• Based on the name of this measure, you can already guess that we're talking about about hundreds of meters.
• Indeed, one hundred square meters is equal to 100 m2.
• In other words, one hundred square meters will be equal to the area of ​​a square with sides of 10 m.
• Accordingly, ten hundred square meters will have 1000 m2.
• 100 acres contain 10,000 m2, and 1000 acres contain 100,000 m2.
• In other words, to calculate how many square meters in given quantity hundredths, you need to multiply the hundredths by 100.

Area units

1 hundred square meters = 100 square meters = 0.01 hectares = 0.02471 acres

• 1 cm 2 = 100 mm 2 = 0.01 dm 2
• 1 dm 2 = 100 cm 2 = 10000 mm 2 = 0.01 m 2
• 1 m 2 = 100 dm 2 = 10000 cm 2
• 1 are (one hundred square meters) = 100 m 2
• 1 ha (hectare) = 10000 m2

How many acres in 1, 10, 100 square meters: table

Conversion table for area units

The system for measuring areas adopted in Russia land plots

• 1 weave = 10 meters x 10 meters = 100 sq.m
• 1 hectare = 1 ha = 100 meters x 100 meters = 10,000 sq.m = 100 acres
• 1 square kilometer = 1 sq. km = 1000 meters x 1000 meters = 1 million sq. m = 100 hectares = 10,000 acres

Reciprocal units

• 1 sq.m = 0.01 acres = 0.0001 hectares = 0.000001 sq.km
• 1 hundred square meters = 0.01 hectares = 0.0001 sq. km

• To calculate how many acres there are in square meters, you need to divide the given number of square meters by 100.
• Thus, in 1 m2 there are 0.01 weave, in 10 m2 - 0.1 weave, and in 100 m2 - 1 weave.

What is a hectare of land?

Hectare- a unit of area in the metric system of measures used for measuring land plots. Field areas are measured in hectares (ha). A hectare is the area of ​​a square with a side of 100 m. This means that 1 hectare is equal to 100,100 square meters, that is, 1 hectare = 10,000 m2.

Abbreviated designation: Russian ha, international ha. The name "hectares" is formed by adding the prefix "hecto..." to the name of the area unit "ar"

1 ha = 100 are = 100 m x 100 m = 10,000 m 2

• A hectare is a unit of measurement for the size of a plot, which is equal to the area of ​​a square with sides of 100 m. A hectare, like a hundred square meters, is used as measuring units mainly used only in agriculture and dacha farming.
• The designation for a hectare looks like “ha”.
• One hectare is equal to 10,000 m2 or 100 acres.

How many square meters in 1, 10, 100, 1000 hectares: table

• In order to calculate how many square meters are in a given number of hectares, you need to multiply the number of hectares by 10,000.
• Thus, in 1 hectare there are 10,000 m2, in 10 hectares - 100,000 m2, in 100 hectares - 1000000 m2, and in 1000 hectares - 10000000 m2.

Thus, one hectare corresponds to 10,000 m2. It can easily accommodate a football field (0.714 hectares) or more than 16 summer cottages (each area is 6 acres). Well, Red Square will be twice as large as one hectare, its area is 24,750 m2.

1 square kilometer is 100 times larger than 1 hectare. We determine similarly: 1 hectare - how many acres there are in the composition. One hundred square meters covers an area of ​​100 square meters. Therefore, in comparison with a hectare, a hundred square meters is 100 times smaller than a hectare.

• 1 weave= 10 x 10 meters = 100 m 2 = 0.01 ha
• 1 hectare (1 ha)= 100 x 100 meters or 10,000 m 2 or 100 acres
• 1 square kilometer (1 km 2)= 1000 x 1000 meters or 1 million m2 or 100 hectares or 10,000 acres
• 1 square meter (1 m2)= 0.01 hundred parts = 0.0001 hectares

How many acres in 1, 10, 100, 1000 hectares: table

• To calculate how many hundred square meters corresponds given number hectare, you need to multiply the number of hectares by 100.
• So, in 1 hectare there are 100 hectares, in 10 hectares - 1000 hectares, in 100 hectares - 10000 hectares, and in 1000 hectares - 100000 hectares.

How many hectares in 1, 10, 100, 1000, 10000 ares, square meters: table

• To calculate how many hectares are contained in a given number of acres, you need to divide the number of acres by 100.
• And to carry out similar calculations with square meters, you need to divide their number by 10,000.
• So, in 1 hundred parts there are 0.01 hectares, in 10 hundred parts - 0.1 hectares, in 100 hundred parts -1 hectares, in 1000 hundred parts - 10 hectares, in 10000 hundred parts - 100 hectares.
• In turn, there are 0.0001 hectares in 1 m2, 0.001 hectares in 10 m2, 0.01 hectares in 100 m2, 0.1 hectares in 1000 m2, and 1 hectare in 10000 m2.

How many square kilometers are in 1 hectare?

1 ha = 10,000 m2

1 km 2 = 100 ha

• Square kilometer is a unit of measurement for the area of ​​land, equal to area square with sides of 1000 meters.
• There are 100 hectares in one square kilometer.
• Thus, to calculate the number of square kilometers in a hectare, you need to divide the given number by 100.
• So, in 1 hectare there are 0.01 km 2

What is 1 ar equal to?

Ar unit of area in the metric system, equal to the area of ​​a square with a side of 10 m

• 1 ar = 10 m x 10 m = 100 m 2 .
• 1 tithe = 1.09254 hectares.

• Arom is a unit of measurement for the size of a plot, equal to the area of ​​a square with sides of 10 m.
• In other words, an ar is equal to a hundred.
• In 1 are there are 100 m2, 1 hundred square meters, 0.01 hectares, 0.0001 km2.

How many ares are there in one hectare?

• There are 100 ares in one hectare, just like one hundred square meters.

What is 1 acre equal to?

Acre land measure used in a number of countries using English system measures (UK, USA, Canada, Australia, etc.).

1 acre = 4840 sq. yards = 4046.86 m2

Ancient Russian units of area measurement

• 1 sq. verst = 250,000 sq. fathoms = 1.1381 km²
• 1 tithe = 2400 sq. fathoms = 10,925.4 m² = 1.0925 ha
• 1 tithe = 1/2 tithe = 1200 sq. fathoms = 5462.7 m² = 0.54627 ha
• 1 octopus = 1/8 tithe = 300 square fathoms = 1365.675 m² ≈ 0.137 hectares.

Length and distance converter Mass converter Bulk and food volume converter Area converter Volume and unit converter in culinary recipes Temperature converter Pressure, mechanical stress, Young's modulus converter Energy and work converter Power converter Force converter Time converter Converter linear speed Flat Angle Thermal Efficiency and Fuel Efficiency Converter Number Converter to various systems notations Converter of units of measurement of quantity of information Exchange rates Sizes of women's clothing and shoes Sizes men's clothing and Shoe Converter angular velocity and rotation speed Acceleration converter Converter angular acceleration Density Converter Specific Volume Converter Moment of Inertia Converter Moment of Force Converter Torque Converter Converter specific heat combustion (by mass) Energy density and specific heat of combustion converter (by volume) Temperature difference converter Coefficient converter thermal expansion Thermal Resistance Converter Converter thermal conductivity Converter specific heat capacity Energy Exposure and Thermal Radiation Power Converter Density Converter heat flow Heat Transfer Coefficient Converter Volume Flow Converter Mass Flow Converter Molar Flow Converter Mass Flow Density Converter Converter molar concentration Converter mass concentration in solution Dynamic (absolute) viscosity converter Kinematic viscosity converter Converter surface tension Vapor permeability converter Vapor permeability and vapor transfer rate converter Sound level converter Microphone sensitivity converter Sound pressure level (SPL) converter Sound pressure level converter with selectable reference pressure Brightness converter Luminous intensity converter Illuminance converter Resolution converter computer graphics Frequency and wavelength converter Optical power in diopters and focal length Optical power in diopters and lens magnification (×) Converter electric charge Linear Charge Density Converter Converter surface density Charge Converter bulk density Charge Converter electric current Linear current density converter Surface current density converter Electric field strength converter Converter electrostatic potential and voltage converter electrical resistance Electrical Resistivity Converter Converter electrical conductivity Electrical conductivity converter Electrical capacity Inductance Converter American Wire Gauge Converter Levels in dBm (dBm or dBmW), dBV (dBV), watts and other units Converter magnetomotive force Tension converter magnetic field Converter magnetic flux Magnetic induction converter Radiation. Absorbed dose rate converter ionizing radiation Radioactivity. Converter radioactive decay Radiation. Exposure dose converter Radiation. Absorbed Dose Converter Decimal Prefix Converter Data Transfer Typography and Image Processing Units Converter Timber Volume Units Converter Calculation molar mass Periodic table chemical elements D. I. Mendeleev

1 square kilometer [km²] = 1,000,000 square meter [m²]

Initial value

Converted value

square meter square kilometer square hectometer square decameter square decimeter square centimeter square millimeter square micrometer square nanometer hectare ar barn square mile sq. mile (US, surveyor) square yard square foot² sq. foot (USA, surveyor) square inch circular inch township section acre acre (USA, surveyor) ore square chain square rod rod² (USA, surveyor) square perch square rod sq. thousandth circular mil homestead sabin arpan cuerda square castilian cubit varas conuqueras cuad cross section of electron tithe (government) tithe economic round square verst square arshin square foot square fathom square inch (Russian) square line Planck area

Kinematic viscosity

More about the area

General information

Area is a quantity geometric figure in two-dimensional space. It is used in mathematics, medicine, engineering and other sciences, such as computing cross section cells, atoms, or pipes, such as blood vessels or water pipes. In geography, area is used to compare the sizes of cities, lakes, countries, and other geographical objects. Population density calculations also use area. Population density is defined as the number of people per unit area.

Units

Square meters

Area is measured in SI units in square meters. One square meter is the area of ​​a square with a side of one meter.

Unit square

A unit square is a square with sides of one unit. Square unit square is also equal to one. IN rectangular system coordinates this square is located at coordinates (0,0), (0,1), (1,0) and (1,1). On complex plane coordinates - 0, 1, i And i+1, where i- imaginary number.

Ar

Ar or weaving, as a measure of area, is used in the CIS countries, Indonesia and some other European countries, to measure small urban objects such as parks, when a hectare is too large. One are is equal to 100 square meters. In some countries this unit is called differently.

Hectare

Real estate is measured in hectares, especially land. One hectare is equal to 10,000 square meters. It has been used since French Revolution, and is used in the European Union and some other regions. Just like the macaw, in some countries the hectare is called differently.

Acre

IN North America and Burma, area is measured in acres. The hectares are not used there. One acre is equal to 4046.86 square meters. An acre was originally defined as the area that a farmer with a team of two oxen could plow in one day.

Barn

Barns are used in nuclear physics to measure the cross section of atoms. One barn is equal to 10⁻²⁸ square meters. The barn is not a unit in the SI system, but is accepted for use in this system. One barn approximately equal to area cross-section of a uranium nucleus, which physicists jokingly called “as huge as a barn.” Barn in English is “barn” (pronounced barn) and from a joke among physicists this word became the name of a unit of area. This unit originated during World War II, and was liked by scientists because its name could be used as a code in correspondence and telephone conversations as part of the Manhattan Project.

Area calculation

The area of ​​the simplest geometric figures is found by comparing them with a square famous square. This is convenient because the area of ​​the square is easy to calculate. Some formulas for calculating the area of ​​geometric figures given below were obtained in this way. Also, to calculate the area, especially of a polygon, the figure is divided into triangles, the area of ​​each triangle is calculated using the formula, and then added. The area of ​​more complex figures is calculated using mathematical analysis.

Formulas for calculating area

• Square: square side.
• Rectangle: product of the parties.
• Triangle (side and height known): the product of the side and the height (the distance from this side to the edge), divided in half. Formula: A = ½ah, Where A- square, a- side, and h- height.
• Triangle (two sides and the angle between them are known): the product of the sides and the sine of the angle between them, divided in half. Formula: A = ½ab sin(α), where A- square, a And b- sides, and α - the angle between them.
• Equilateral triangle: side squared divided by 4 and multiplied by Square root out of three.
• Parallelogram: the product of a side and the height measured from that side to the opposite side.
• Trapezoid: sum of two parallel sides, multiplied by the height, and divided by two. The height is measured between these two sides.
• Circle: the product of the square of the radius and π.
• Ellipse: product of semi-axes and π.

Surface Area Calculation

Find the surface area of ​​prime volumetric figures, such as prisms, can be developed by developing this figure on a plane. It is impossible to obtain a development of the ball in this way. The surface area of ​​a ball is found using the formula by multiplying the square of the radius by 4π. From this formula it follows that the area of ​​a circle is four times less area surface of a ball with the same radius.

Surface areas of some astronomical objects: Sun - 6,088 x 10¹² square kilometers; Earth - 5.1 x 10⁸; Thus, the surface area of ​​the Earth is approximately 12 times smaller than the surface area of ​​the Sun. The Moon's surface area is approximately 3.793 x 10⁷ square kilometers, which is about 13 times smaller than the Earth's surface area.

Planimeter

The area can also be calculated using a special device - a planimeter. There are several types of this device, for example polar and linear. Also, planimeters are analogue and digital. In addition to other functions, digital planimeters can be scaled, making it easier to measure features on a map. The planimeter measures the distance traveled around the perimeter of the object being measured, as well as the direction. The distance traveled by the planimeter parallel to its axis is not measured. These devices are used in medicine, biology, technology, and agriculture.

Theorem on properties of areas

According to the isoperimetric theorem, of all figures with the same perimeter, the circle has the largest area. If, on the contrary, we compare figures with the same area, then the circle has the smallest perimeter. The perimeter is the sum of the lengths of the sides of a geometric figure, or the line that marks the boundaries of this figure.

Geographical features with the largest area

Country: Russia, 17,098,242 square kilometers, including land and water. The second and third largest countries by area are Canada and China.

City: New York is a city with the most large area 8683 square kilometers. The second largest city by area is Tokyo, occupying 6993 square kilometers. The third is Chicago, with an area of ​​5,498 square kilometers.

City Square: The largest square, covering 1 square kilometer, is located in the capital of Indonesia, Jakarta. This is Medan Merdeka Square. The second largest area, at 0.57 square kilometers, is Praça doz Girascoes in the city of Palmas, Brazil. The third largest is Tiananmen Square in China, 0.44 square kilometers.

Lake: Geographers debate whether the Caspian Sea is a lake, but if so, then it is the most big lake in the world with an area of ​​371,000 square kilometers. The second largest lake by area is Lake Superior in North America. It is one of the lakes of the Great Lakes system; its area is 82,414 square kilometers. The third largest lake in Africa is Lake Victoria. It covers an area of ​​69,485 square kilometers.

square kilometer- - Topics Oil and gas industry EN square kilometersq.km …

square kilometer- measure of areas metric system= 1,000,000 sq. meters 0.38610 English sq. miles = 0.87869 sq. versts = 91.5298 tithes; The abbreviation for square kilometer legalized in the USSR: Russian “km2” or “sq. km", Latin "km2" ...

number of inhabitants per square kilometer- - [A.S. Goldberg. English-Russian energy dictionary. 2006] Topics: energy in general EN inhabitants per square kilometerinh/km2 … Technical Translator's Guide

- (from the Greek chilioi thousand, and meter). French linear measure is about 469 Russian. soot Dictionary foreign words, included in the Russian language. Chudinov A.N., 1910. KILOMETER 1000 meters = 14/15 versts, or 468.7 fathoms. Complete dictionary foreign words... ... Dictionary of foreign words of the Russian language

The request for "km" is redirected here, see also "KM" Kilometer (abbreviated km, km) is a widely used unit of distance measurement that is a multiple of the meter. 1 km = 1000 m = 0.621 miles = 0.9374 versts = 1094 yards = 3281 feet = 1.057 10−13 light years ... Wikipedia

Area is a quantity that in some sense corresponds to the size of a surface. Contents 1 Formal definition 2 Units of measurement 2.1 Metric units... Wikipedia

Square kilometer (km², km², sq.km) is a unit of area measurement that is a multiple of a square meter. 1 km² is equal to: the area of ​​a square with a side of 1 kilometer; 1,000,000 m²; 100 hectares; 0.386 102 square miles; 247,105,381 acres. Back: 1 m² = 0.000... ... Wikipedia

Square kilometer (km², km², sq.km) is a unit of area measurement that is a multiple of a square meter. 1 km² is equal to: the area of ​​a square with a side of 1 kilometer; 1,000,000 m²; 100 hectares; 0.386 102 square miles; 247,105,381 acres. Back: 1 m² = 0.000... ... Wikipedia

Abbreviations- And on the bill of exchange means that the bill has been accepted. a., arsh. arshin. and ar. a2. square arshin, a3. cubic arshin. an. f. (an. pound) english pound. b. g., b/y next year. b. m., b/m next month. B.M.O., b.m/o without my responsibility... ... Reference commercial dictionary

Books

• Mysterious places of Russia, Afonkin Sergey Yurievich. People are always attracted to the incomprehensible, mysterious, unknown. It was this thrust that forced the brave captains of past centuries to rush their ships towards the horizon. Without the desire to reveal...
• Secrets of the Vatican, Cyrus Shahard. The Vatican is the thousand-year-old center of Roman Catholicism, a state within a state and the world's smallest sovereign power, occupying just one square kilometer. However, the history of this...

Kilometers when measuring a road, simply multiply the length of the road by its width. Also first convert the width of the road to kilometers. Since the width of the road is usually specified (measured) in meters, simply divide the width of the road (in meters) by 1000. If the width of the road is not constant, then convert each section that has the same width to square kilometers. Then add up the resulting areas. If the accuracy of the calculations is not important, take its average width as the width of the road. If the road is federal highway, then find its width in the relevant reference books (for example, atlases of motorists). For rough calculations, take the width of the central highway equal to 8 (0.008 km) - this is the average width of the federal highway route.

Search engines They also know how to convert area units. Download for example: home page Google search engine and enter the appropriate query. Say, if you need to convert 1587 m?, then the request might look like this: “1587 square to square kilos meters" The Google calculator will recalculate and display the result: “1587 (sq. meters) = 0.001587 sq. kilometer".

Sources:

• size in square meters

To solve problems correctly, you need to ensure that the units of measurement correspond to a unified system. Traditionally, for solving mathematical and physical problems The international measurement system is used. If quantities are specified in other systems, they must be converted to International Standard (SI).

You will need

• - tables of multiples and submultiples;
• - calculator.

Instructions

One of the main quantities that are measured in applied sciences- length. Traditionally it was measured in steps, elbows, miles, etc. Today the basic unit of length is 1 meter. Fractional values ​​from it are , etc. For example, to convert centimeters to meters, you need to divide them by 100. If the length is measured in kilometers, convert it to meters by multiplying by 1000. To convert national units lengths, use appropriate coefficients.

Time is measured in seconds. Other popular units of time and clocks. To convert minutes to , multiply them by 60. Convert hours to seconds by multiplying by 3600. For example, if the time during which the incident occurred is 3 hours and 17 minutes, then convert it to seconds in this way: 3∙3600+17∙60= 11820 pp.

Speed, as a derived quantity, is measured in meters per second. Another popular one is per hour. To convert the speed to m/s, multiply it by 1000 and divide by 3600. For example, if the speed of a cyclist is 18 km/h, then this value in m/s will be equal to 18∙1000/3600=5 m/s.

Length and distance converter Mass converter Converter of volume measures of bulk products and food products Area converter Converter of volume and units of measurement in culinary recipes Temperature converter Converter of pressure, mechanical stress, Young's modulus Converter of energy and work Converter of power Converter of force Converter of time Linear speed converter Flat angle Converter thermal efficiency and fuel efficiency Converter of numbers in various number systems Converter of units of measurement of quantity of information Currency rates Women's clothing and shoe sizes Men's clothing and shoe sizes Angular velocity and rotation frequency converter Acceleration converter Angular acceleration converter Density converter Specific volume converter Moment of inertia converter Moment of force converter Torque converter Specific heat of combustion converter (by mass) Energy density and specific heat of combustion converter (by volume) Temperature difference converter Coefficient of thermal expansion converter Thermal resistance converter Thermal conductivity converter Specific heat capacity converter Energy exposure and thermal radiation power converter Heat flux density converter Heat transfer coefficient converter Volume flow rate converter Mass flow rate converter Molar flow rate converter Mass flow density converter Molar concentration converter Mass concentration in solution converter Dynamic (absolute) viscosity converter Kinematic viscosity converter Surface tension converter Vapor permeability converter Vapor permeability and vapor transfer rate converter Sound level converter Microphone sensitivity converter Sound Pressure Level (SPL) Converter Sound Pressure Level Converter with Selectable Reference Pressure Luminance Converter Luminous Intensity Converter Illuminance Converter Computer Graphics Resolution Converter Frequency and Wavelength Converter Diopter Power and Focal Length Diopter Power and Lens Magnification (×) Electric charge converter Linear charge density converter Surface charge density converter Volume charge density converter Electric current converter Linear current density converter Surface current density converter Electric field strength converter Electrostatic potential and voltage converter Electrical resistance converter Electrical resistivity converter Electrical conductivity converter Electrical conductivity converter Electrical capacitance Inductance converter American wire gauge converter Levels in dBm (dBm or dBm), dBV (dBV), watts, etc. units Magnetomotive force converter Magnetic field strength converter Magnetic flux converter Magnetic induction converter Radiation. Ionizing radiation absorbed dose rate converter Radioactivity. Radioactive decay converter Radiation. Exposure dose converter Radiation. Absorbed dose converter Decimal prefix converter Data transfer Typography and image processing unit converter Timber volume unit converter Calculation of molar mass D. I. Mendeleev’s periodic table of chemical elements

1 square kilometer [km²] = 100 hectares [ha]

Initial value

Converted value

square meter square kilometer square hectometer square decameter square decimeter square centimeter square millimeter square micrometer square nanometer hectare ar barn square mile sq. mile (US, surveyor) square yard square foot² sq. foot (USA, surveyor) square inch circular inch township section acre acre (USA, surveyor) ore square chain square rod rod² (USA, surveyor) square perch square rod sq. thousandth circular mil homestead sabin arpan cuerda square castilian cubit varas conuqueras cuad cross section of electron tithe (government) tithe economic round square verst square arshin square foot square fathom square inch (Russian) square line Planck area

More about the area

General information

Area is the size of a geometric figure in two-dimensional space. It is used in mathematics, medicine, engineering and other sciences, for example in calculating the cross-section of cells, atoms, or pipes such as blood vessels or water pipes. In geography, area is used to compare the sizes of cities, lakes, countries, and other geographic features. Population density calculations also use area. Population density is defined as the number of people per unit area.

Units

Square meters

Area is measured in SI units in square meters. One square meter is the area of ​​a square with a side of one meter.

Unit square

A unit square is a square with sides of one unit. The area of ​​a unit square is also equal to one. In a rectangular coordinate system, this square is located at coordinates (0,0), (0,1), (1,0) and (1,1). On the complex plane the coordinates are 0, 1, i And i+1, where i- imaginary number.

Ar

Ar or weaving, as a measure of area, is used in the CIS countries, Indonesia and some other European countries, to measure small urban objects such as parks, when a hectare is too large. One are is equal to 100 square meters. In some countries this unit is called differently.

Hectare

Real estate, especially land, is measured in hectares. One hectare is equal to 10,000 square meters. It has been in use since the French Revolution, and is used in the European Union and some other regions. Just like the macaw, in some countries the hectare is called differently.

Acre

In North America and Burma, area is measured in acres. The hectares are not used there. One acre is equal to 4046.86 square meters. An acre was originally defined as the area that a farmer with a team of two oxen could plow in one day.

Barn

Barns are used in nuclear physics to measure the cross section of atoms. One barn is equal to 10⁻²⁸ square meters. The barn is not a unit in the SI system, but is accepted for use in this system. One barn is approximately equal to the cross-sectional area of ​​a uranium nucleus, which physicists jokingly called “as huge as a barn.” Barn in English is “barn” (pronounced barn) and from a joke among physicists this word became the name of a unit of area. This unit originated during World War II, and was liked by scientists because its name could be used as a code in correspondence and telephone conversations within the Manhattan Project.

Area calculation

The area of ​​the simplest geometric figures is found by comparing them with the square of a known area. This is convenient because the area of ​​the square is easy to calculate. Some formulas for calculating the area of ​​geometric figures given below were obtained in this way. Also, to calculate the area, especially of a polygon, the figure is divided into triangles, the area of ​​each triangle is calculated using the formula, and then added. The area of ​​more complex figures is calculated using mathematical analysis.

Formulas for calculating area

• Square: square side.
• Rectangle: product of the parties.
• Triangle (side and height known): the product of the side and the height (the distance from this side to the edge), divided in half. Formula: A = ½ah, Where A- square, a- side, and h- height.
• Triangle (two sides and the angle between them are known): the product of the sides and the sine of the angle between them, divided in half. Formula: A = ½ab sin(α), where A- square, a And b- sides, and α - the angle between them.
• Equilateral triangle: side squared divided by 4 and multiplied by the square root of three.
• Parallelogram: the product of a side and the height measured from that side to the opposite side.
• Trapezoid: the sum of two parallel sides multiplied by the height and divided by two. The height is measured between these two sides.
• Circle: the product of the square of the radius and π.
• Ellipse: product of semi-axes and π.

Surface Area Calculation

You can find the surface area of ​​simple volumetric figures, such as prisms, by unfolding this figure on a plane. It is impossible to obtain a development of the ball in this way. The surface area of ​​a ball is found using the formula by multiplying the square of the radius by 4π. From this formula it follows that the area of ​​a circle is four times less than the surface area of ​​a ball with the same radius.

Surface areas of some astronomical objects: Sun - 6,088 x 10¹² square kilometers; Earth - 5.1 x 10⁸; Thus, the surface area of ​​the Earth is approximately 12 times smaller than the surface area of ​​the Sun. The Moon's surface area is approximately 3.793 x 10⁷ square kilometers, which is about 13 times smaller than the Earth's surface area.

Planimeter

The area can also be calculated using a special device - a planimeter. There are several types of this device, for example polar and linear. Also, planimeters are analogue and digital. In addition to other functions, digital planimeters can be scaled, making it easier to measure features on a map. The planimeter measures the distance traveled around the perimeter of the object being measured, as well as the direction. The distance traveled by the planimeter parallel to its axis is not measured. These devices are used in medicine, biology, technology, and agriculture.

Theorem on properties of areas

According to the isoperimetric theorem, of all figures with the same perimeter, the circle has the largest area. If, on the contrary, we compare figures with the same area, then the circle has the smallest perimeter. The perimeter is the sum of the lengths of the sides of a geometric figure, or the line that marks the boundaries of this figure.

Geographical features with the largest area

Country: Russia, 17,098,242 square kilometers, including land and water. The second and third largest countries by area are Canada and China.

City: New York is the city with the largest area of ​​8683 square kilometers. The second largest city by area is Tokyo, occupying 6993 square kilometers. The third is Chicago, with an area of ​​5,498 square kilometers.

City Square: The largest square, covering 1 square kilometer, is located in the capital of Indonesia, Jakarta. This is Medan Merdeka Square. The second largest area, at 0.57 square kilometers, is Praça doz Girascoes in the city of Palmas, Brazil. The third largest is Tiananmen Square in China, 0.44 square kilometers.

Lake: Geographers debate whether the Caspian Sea is a lake, but if so, it is the largest lake in the world with an area of ​​371,000 square kilometers. The second largest lake by area is Lake Superior in North America. It is one of the lakes of the Great Lakes system; its area is 82,414 square kilometers. The third largest lake in Africa is Lake Victoria. It covers an area of ​​69,485 square kilometers.