Posted by **Thomas** on Sunday, January 5, 2014 at 4:55pm.

The area of circle c is 81 pi . if the radius of the circle is doubled, what is the circumference of the new circle ?

please answer and explain

- math -
**Ms. Sue**, Sunday, January 5, 2014 at 4:57pm
162 pi

- math -
**Thomas**, Sunday, January 5, 2014 at 5:01pm
my answer is 162 pi too, but the answer is

a. 18 pi

b. 36 pi

c. 36 pi^2

d. 324 pi

e. 324 pi^2

- math -
**Steve**, Sunday, January 5, 2014 at 6:42pm
if a = 81pi, r = 9

if r = 18, c = 36pi

## Answer This Question

## Related Questions

- math - A circle has an area of 25 pi cm^2.If a circle is drawn within that ...
- math - The number of square units in the area of circle P is equal to the number...
- triggg - Suppose a circle has a radius of 4.5 inches. If you double the radius ...
- 8th grade math - circle A has a raduis that is twice the length og the raduis of...
- math - I'm asked to find the circumference of a circle to the nearest tenth and ...
- Algebra - The Circumference and area of a circle of radius r are givin by 2 [pie...
- Geometry - A circle with a radius of 1/2 ft is dilated by a scale factor of 8. ...
- MATH HELP PLEASE - You are given two different circles. The diameter of the ...
- math - The circumference of a circle = 20 pi. If the circle is cut in half, what...
- math - the radius of a circle when the numeric values of the circumference and ...

More Related Questions