an artist wishes to paint a circular region on a square poster that is 4 feet on a side . if the area of the circular region is to be 1 / 2 the area of the poster , what must be the radius of the circular region in feet ?
"area of the poster is 4 x 4 = 16 1 / 2 the area = 8 pi * r ^ 2 = 8 r ^ 2 = 8 / pi r = sqrt ( 8 / pi ) answer : c"
sqrt(divide(divide(square_area(4), 2), const_pi))