SOLUTION: The circumference of a circle is 42 pi inches. What is the area of the circle to the nearest tenth of an inch? Which answer is it? a. 66.0 in.^2 b. 131.4 in.^2 c. 1185.

Algebra ->  Circles -> SOLUTION: The circumference of a circle is 42 pi inches. What is the area of the circle to the nearest tenth of an inch? Which answer is it? a. 66.0 in.^2 b. 131.4 in.^2 c. 1185.      Log On


   

Question 635189: The circumference of a circle is 42 pi inches. What is the area of the circle to the nearest tenth of an inch?
Which answer is it?
a. 66.0 in.^2
b. 131.4 in.^2
c. 1185.4 in.^2
d. 1385.4 in.^2
Found 2 solutions by ewatrrr, richwmiller:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

The circumference of a circle is 42 pi inches.  2pi%2Ar+=+42%2Api   r = 21

A = pi%2Ar%5E2+=+3.14%2A%2821in%29%5E2 = 1385.4 in^2

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
2*pi*r=42pi
r=21
pi*21^2
d) 1385 .4 in^2