To find the circumference of the semicircle, first multiply the diameter, 2, by pi, or 3.14. 2*3.14 = 6.28. This is the circumference of the hypothetical full circle, which we must divide by 2 because it is a semicircle! So the circumference is 3.14. Now, find the perimeter of the rectangular portion, which is 5+5+2 = 12. Now, add.
3.14 + 12 = 15.14.
The answer is d. 15.14 ft.
Hope that helped you.