The perimeter of the rectangle is equal to the sum of the lengths of the three sides not bound by the semicircle:
10 ft + 4 ft + 10 ft = 24 ft
The perimeter of the semicircle is (1/2)*2*pi*r. The diameter of the circle is 4 ft, so the radius is 2 ft.
(1/2)*2*pi*2 = 6.28 ft
Add the perimeters of the rectangle and semicircle to find the total perimeter of the figure:
24 ft + 6.28 ft = 30.28 ft
Therefore, the answers is 30.28 ft.