Circles and radius

Question

Find the radius of each circle with the given measurement

π = pi

 

Part A:

 

C=36π cm

 

Part B:

C=42π ft

 

Part C:

A=121π cm²

 

Part D:

A= 734.41π ft²

Answer 1

The formula for circumference:

 

C = 2πr

 

 

The formula for area:

A = πr²

 

 

Apply the formula for circumference in parts A and B.  Solve for r.

Apply the formula for area in parts C and D.  Solve for r.