Written below: C equals two pi r., The formula for the circumference of a circle uses either the diameter or the radius of the circle. End of image gallery Question ...

The radius of the circle is 8 cm. Substitute 𝒓 = 8 into the formula for the area of the circle. Multiply π by the square of the radius. 3۰14 × 82 = 200۰96.

The radius can be used to calculate a circle's diameter, area and circumference. Likewise, ... you can construct a formula in Microsoft Excel to do the math for you. Open Microsoft Excel.

In the book Elementary Algebra for College Students, Allen R. Angel discusses the formula for area and circumference, which you can use to measure a hockey puck (144). Area = ...

The area of this square is AZ squared, or 3.1415258. This differs from the area of the circle by less than 0.0001. Thus, Crockett Johnson approximately squared the circle.