Solve for A

Question

R1= the sqaure root of A/π -R2^2

Answer 1

R1 = sqaure root of (A/π -R2^2)

Take square each side

r1^2 = A/π -R2^2

Add R2^2 to each side

R1^2 + R2^2 = A/π

Multiply each side by π

π(R1^2 + R2^2 ) = A