What is the formula for finding the radius of a circle?

Answer 1

AnswerR = D/2

If you know the diameter, divide it by two.

R = C/2pi

If you know the circumference, divide it by 2pi.

R = the square root of the area divided by pi.

If you know the area, divide it by pi and find the square root of that number.

If you don't know any of the measurements, draw a square around the circle where all four sides touch it. The radius will be half of one of the sides.

Answer 2

It depends on what information you do have.