To solve this we are going to use the formula for the area of a circle: [tex]A= \frac{1}{4} \pi d^2 [/tex]
where
[tex]A[/tex] is the area of the circle
[tex]d[/tex] is the diameter of the circle
We know from our problem that the area of our circle is 10 inches long, so [tex]d=10in[/tex]. Lets replace that value in our formula to find [tex]A[/tex]:
[tex]A=\frac{1}{4} \pi (10in)^2[/tex]
[tex]A=78.54in^2[/tex]
We can conclude that the correct answer is: 78.54 square inches, or in centimeters: 506.7 square cm.