What is the area of a circle with diameter 12 kilometers?

Here is the answer to questions like: how to find the area of a circle with diameter 12 kilometers?

Use the this circle area calculator below to find the area of a circle given its diameter, or other parameters. To calculate the area, you just need to enter a positive numeric value in one of the 3 fields of the calculator. You can also see at the bottom of the calculator, the step-by-step solution.

Area of a Circle Calculator

Formulas:

Circle area formula

Inputs:

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Result:

The area of a circle with diameter 12 is 113.1

Solution Steps:

Area of a cicle in terms of radius:

Area = π . r2 = 3.14 × 62 = 113.1 square kilometers.

In terms of diameter:

Area = π . (d/2)2 = 3.14 × (12/2)2 = 3.14 × (6)2 = 113.1 square kilometers.

In terms of circumference:

Area = C2/(4π) = 37.72/ = 1421.29/(4 × 3.14) = 1421.29/(12.56) = 113.1 square kilometers.

Note: for simplicity, some results may be rounded to nearest hundredth and π was rounded to 3.14. See formula details below in this page.

A circle of radius = 6 or diameter = 12 or circunference = 37.7 kilometers has an area of 113.1 square kilometers which is equal to:

  • 113100000 square meters (m²)
  • 1131000000000 square centimeters (cm²)
  • 27950 acres (ac)
  • 11310 hectares (ha)
  • 43.67 square miles (mi²)
  • 135300000 square yards (yd²)
  • 1217000000 square feet (ft²)
  • 175300000000 square inches (in²)
  • Formula for area of a circle

    Here a three ways to find the area of a circle (formulas):

    Circle area formula in terms of radius

    Circle area formula in terms of radius

    Circle area formula in terms of diameter

    Circle area formula in terms of diameter

    Circle area formula in terms of circumference

    Circle area formula in terms of circumference

    See below some definitions related to the formulas:

    Circumference

    Circumference is the linear distance around the circle edge.

    Radius

    The radius of a circle is any of the line segments from its center to its perimeter. The radius is half the diameter or r = d/2.

    Diameter

    The diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. The diameter is twice the radius or d = 2r.

    The Greek letter π

    π represents the number Pi which is defined as the ratio of the circumference of a circle to its diameter or π = C / d. For simplicity, you can use Pi = 3.14 or Pi = 3.1415. Pi is an irrational number. The first 100 digits of Pi are: 3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 ...

    Note:

    If you input the radius in centimeters, you will get the answer in square centimeters (cm²), if in inches, will get the answer in square inches (in²) and so on ...

    Circumference is often misspeled as circunference.

    You can use our area unit converter to see the results in other units.

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