# Question: let afrafr be the area of a circle of radius...

###### Question details

Let A=f(r)A=f(r) be the area of a circle of radius r.

(a) Write a formula for f(r)=f(r)=

(b) Which expression represents the area of a circle whose
radius is increased by 20%?

**A.** 0.2f(r)0.2f(r)

**B.** f(r+0.2)f(r+0.2)

**C.** f(1.2r)f(1.2r)

**D.** f(20+r)f(20+r)

**E.** f(r)+0.2f(r)+0.2

(c) By what percent does the area increase if the radius is
increased by 20%?

% (round to the nearest 0.01%) help (numbers)