Problem: an artist wishes to paint a circular region on a square poster that is 2.4 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 ?
Rationale: "area of the poster is 2.4 x 2.4 = 5.76 1 / 2 the area = 2.88 pi * r ^ 2 = 2.88 r ^ 2 = 2.88 / pi r = sqrt ( 2.88 / pi ) answer ( b )"
annotated_formula: sqrt(divide(divide(square_area(2.4), 2), const_pi))