Question

Please please please help

Answer 1

D

Explanation:

given A = π(R² - r²)

divide both sides by π, hence

R² - r² =
`(A)/(\pi )`

add r² to both sides

R² =
`(A)/(\pi )` + r²

Take the square root of both sides

R =
`√(A/\pi+r^2 )` → D