geometry
posted by Mary .
I need to find the perimeter of square that has a semicircle (located inside of the square) with a radius of 10 in and it appears that the square is 10 inches as well. I tried the equation 1/2*3.14*10= 15.7, but I don't think it is correct please help!!

If a complete semicircle is inside a square, it could be tangent to one side of the square and end at the midpoints of two adjacent sides. It would then have a radius of 10, the side of the square would be 20 long and the square's perimeter would be 80.

I still don't quite understand.