What is the area of a circle with circumference 19.4 kilometers?

Here is the answer to questions like: how to find the area of a circle with circumference 19.4 kilometers?

Use the this circle area calculator below to find the area of a circle given its circumference, 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.

Inputs:

 Radius: or Diameter: or Circumference: Unit: centimeter foot inch kilometer meter mile yard

Result:

The area of a circle with circumference 19.4 is 29.95

Area of a cicle in terms of radius:

Area = π . r2 = 3.14 Ã— 3.092 = 29.95 square kilometers.

In terms of diameter:

Area = π . (d/2)2 = 3.14 Ã— (6.18/2)2 = 3.14 Ã— (3.09)2 = 29.95 square kilometers.

In terms of circumference:

Area = C2/(4π) = 19.42/ = 376.36/(4 Ã— 3.14) = 376.36/(12.56) = 29.95 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 = 3.088 or diameter = 6.175 or circunference = 19.4 kilometers has an area of 29.95 square kilometers which is equal to:

• 29950000 square meters (mÂ²)
• 299500000000 square centimeters (cmÂ²)
• 7401 acres (ac)
• 2995 hectares (ha)
• 11.56 square miles (miÂ²)
• 35820000 square yards (ydÂ²)
• 322400000 square feet (ftÂ²)
• 46420000000 square inches (inÂ²)
• Formula for area of a circle

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

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.

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 (cmÂ²), if in inches, will get the answer in square inches (inÂ²) and so on ...

Circumference is often misspeled as circunference.

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