Question

Which of the following expressions correctly shows the relationship between the circumference and the area of a circle?(1 point)
Responses

Cd=π
𝐶
𝑑
=
𝜋

Start Fraction upper C over d End Fraction equals pi

C2=4πA
𝐶
2
=
4
𝜋
𝐴

upper C squared equals 4 pi upper A

A=πr2
𝐴
=
𝜋
𝑟
2

upper A equals pi r squared

C=2πr

Answer 1

C^2 = 4πA

Derivation: C = 2πr and A = πr^2. Substitute r^2 = A/π into C^2 = (2πr)^2 = 4π^2 r^2 to get C^2 = 4π^2·(A/π) = 4πA.