Answer:
42.84 cm
Explanation:
1) Find the perimeter of the top trapezoid. (In cm) 6 + 8 + 12 + 10 = 36 cm
2) Find the circumference of the semicircle with the formula 0.5(pie times D) where D is the diameter. Another formula is 0.5(pie times 2r) where r is the radius. Approximate pie to 3.14 so we should get 0.5 * 3.14 * 12 = 18.84 cm
3) We do not need the length of the base of the trapezoid so we take 36 + 18.84 - 12 = 42.84 cm