Answer:
61%
Explanation:
Because there are 4 semicircles, 18/4=4.5, so the area of each semicircle is 4.5 pi. Therefore the area of a whole circle is 9 pi, so the radius of the circle is 3. That means the diameter of the circle, which is also the side of the square, is 6, so the area of the square is 36. Therefore the percent of the design that is green fabric is:
18pi/18pi+36
= 56.52/92.52
= about 0.611, which rounds to 61%.