Answer:
- A = 9π
- r = 4
- A = 1/4π
- r = 10
Step-by-step explanation:
The given formula can be used to find the area when the radius is known.
r = 3, A = 3²π = 9π
r = 1/2, A = (1/2)²π = 1/4π
The formula can be solved to give the radius when the area is known:
r = √(A/π)
A = 16π, r = √(16π/π) = 4
A = 100π, r = √(100π/π) = 10
