It can be determined easily using a formula A pr2 Pi r-squared where r is the radius of the circle. Here are the circle equations. So if you measure the diameter of a circle to be 85 cm you would have.
The circumference C of a circle is a measure of the distance around the circle.
So if you measure the diameter of a circle to be 85 cm you would have. You can calculate the circumference of any circle if you know either the radius or diameter. Find the area. X-a2 y-b2 r2.