Circle & Rectangle

Hint: Draw an imaginary line through opposite vertices of the rectangle. Where they cross is the center of the circle. The radius is the length of one of those lines. Can you somehow make use of the pythagorean theorem to determine the length of one of those lines?

ok
Let's see:

8 feet long and 6 feet wide = the legs of the hypotenuse in this case.

6^2 + 8^2 = diagonal^2

100 = diagonal^2

10 = diagonal

diagonal/2 = 10/2 = 5 feet for the radius, right?

Is this correct?

yep