Credit: Chris McClanahan CC-BY-SA 2.0
Q:

# How do you calculate the square footage of a circle?

A:

The area of a circle is determined by the formula: A = π r2. You can easily calculate the area of a circle in under a minute. All you need is a calculator, a circle to measure and a tool with which to measure, such as a ruler.

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1. ### Determine the radius of the circle

Use a ruler or similar tool to measure the radius of the circle. This is the length of the line from the middle of the circle to any point on its edge.

2. ### Convert the radius to feet

If the radius of the circle was measured in inches, multiply the number by 0.0833333 using the calculator. If it was measured in centimeters, multiply the number by 0.0328084.

3. ### Use the formula to calculate the area

Multiply the radius (in feet) by itself. Then multiply this number by pi (approximately 3.141592). There should be a pi (π) button on your calculator to make this easier. This number is the area of the circle in square feet.

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## Related Questions

• A:

A triangle is a three-sided polygon, existing in various lengths and forms. To calculate square footage of a triangular shape, you need to calculate the area of the triangle with feet as the unit of measurement.

Filed Under:
• A:

The equation for the area of a circle is pi times the square of the radius or A = πr2. Calculating the area of a sector involves figuring out what fraction of the circle's area the sector covers.

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• A:

The area of any simple shape, such as a circle, triangle or rectangle, can be found by taking a series of measurements from the shape and plugging them into a formula. The necessary formula varies according to the shape but works for all shapes of that type.