Posted by **Kenya** on Wednesday, May 14, 2008 at 11:20pm.

How do you do these problems???

What is the radius of a circle that its area is 254.5 square inches???

What is the diameter of a circle if its area is 132.7 square meters??

I don't understand this because of the thing that says "square"

- Adv. Math -
**Reiny**, Thursday, May 15, 2008 at 12:08am
area of circle = pi(r^2)

so for the first one :

254.5 = pi(r^2), divide both sides by pi

81 = r^2 , now take the square root of both sides

9 = r

do the second one the same way, double the answer you get for r to get the diameter.

- Adv. Math -
**Ms. Sue**, Thursday, May 15, 2008 at 11:27am
For an explanation of "square" in a circle, check this site.

http://www.mathgoodies.com/lessons/vol2/circle_area.html

## Answer this Question

## Related Questions

- Math - Two perpendicular diamters(cutting each other at right angles) of a ...
- Geometery - How do I solve this? On my assignment it says find the area inside ...
- math - The area of a circle is given by the formula A = ğr2, where r is the ...
- geometry - I need to find the area of the shaded portion of a circle with a ...
- Algebra - The area of a circle is given by the formula A+pier^2, where r is the ...
- algebra 1 - A high school wrestling mat must be a square with 38-foot sides and ...
- math - The area of a circle with radius r given by the formula A = pi r^2. If a...
- Math word problem - A small circular pool is enclosed in a square. Find the area...
- math - From a piece of pin in the shape of a square 6 inches on a side, the ...
- math - If the number of square inches in the area of a circle is equal to the ...

More Related Questions