area of the circle?

Question

http://i2.photobucket.com/albums/y48/xxkrystinaxx9/7_17o.gif

In the diagram above, if the circle with center F has an area of
72 , what is the area of the circle with center G?

A 18
B 24
C 30
D 36
E 48

Answer 1

Area_F = πr² = 72
For F ... r² = (72) / π
Area_G = πr² = 72
Where r = 1/2r of F's r
So for G, in terms of F's r;
(r/2)² = (X) / π
... G areas would therefor be 1/4 (result of (1/2)² = 18

Answer 2

What "F"? I don't see one in the image you linked.

EDIT: OK, I see. You swapped the two links in the two problems you posted.

Notice that the diameter of the "G" circle is the radius of the "F" circle. So the radius of "G" is half of that of the "F". If pi*(r^2) = 72, then pi*(r/2)^2 = (1/4)pi*(r^2) = (1/4)*72 = 18.

Answer 3

I think you've placed the wrong pictures on both of your posts (circumference and area).
assuming the area is 72 then the answer is 18.

Answer 4

The picture I see has only the letters O, C, and D. F and G are nowhere to be found. You must have got your pictures confused.

Answer 5

Not enough info on the picture to tell, but I'm going to guess E.

Answer 6

Ther is no F, you've put a wrong picture.

Answer 7

pie r squared is the way to answer this