The radius of circle A is 9 times greater than the radius of circle B. Which of the following statements is true?

A.The area of circle B is 9 times greater than the area of circle A.
B.The area of circle A is 9 times greater than the area of circle B
C.The area of circle B is 81 times greater than the area of circle A.
D.The area of circle A is 81 times greater than the area of circle B.

1 answer

no, the answer is d)

let the radius of first circle be r
area = πr62
let the area of 2nd circle be 9r
area =π(9x)^2 = 81πr^2, which is 81 times larger.