Question

If x = 5 units, y = 6 units, and h = 6 units, find the area of the trapezoid shown above using decomposition. A. 102 square units B. 30 square units C. 66 square units D. 48 square units

Answer 1

C. 66 square units

Explanation:

The area of the middle rectangle would by base × height, or y × h, or 6 × 6.

The area is 36.

The area for one triangle would 1/2 × base × height.

(But since there are two triangles to solve for, the 1/2 is not necessary, and we can just do base × height again.)

So, it would be x × h, or 5 × 6.

The area is 30.

Combine both areas to get the whole area of 66 units²