area of a circle sat

[lily]

The area of a circle is . If the radius of this circle is tripled, what is the new area?

(A)

(B)

(C)

(D)

Thanks

[kadence]

The area of a circle with radius is given by the following formula


So, (1)

If the radius of this circle is tripled i.e. the new area is equal to (2)

From (1) and (2) we have that the new area is


Therefore the correct answer is (C).

Hope these help!!

[lily]

Thank you kadence!