Thursday

April 24, 2014

April 24, 2014

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

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 12:08amarea 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 11:27amFor an explanation of "square" in a circle, check this site.

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

**Related Questions**

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 number of square units in the area of circle P is equal to the number...

8th grade math - circle A has a raduis that is twice the length og the raduis of...

7th Grade Math - If a diameter of a circle (which is 18 inches) is tripled, can ...

math - 1.) Calculate the area of a circle with radius 8.5 inches. . 2.) ...

Geometry - A dartboard consists of five concentric circles. The radius of the ...

math - The area of a circle with radius r is given by the formula A=πr^2. ...

area of circle - My circle has a radius of 8ft. What is the distance of the ...

Math - Circle C has radius 4 inches. Circle D had radius 9 inches. These two ...