Computing Area of Two-dimensional Solids – Parallelograms and Trapezoids

in Aviation Mathematics

Parallelogram

A parallelogram is a four-sided figure with two pairs of parallel sides. [Figure 1-17] Parallelograms do not necessarily have four right angles. The formula for the area of a parallelogram is:

Area = Length × Height = L × H


Figure 1-17. Parallelogram.

Figure 1-17. Parallelogram.

Trapezoid

A trapezoid is a four-sided figure with one pair of parallel sides. [Figure 1-18] The formula for the area of a trapezoid is:

Area = 1⁄2 (Base1 + Base2) × Height

Figure 1-18. Trapezoid.

Figure 1-18. Trapezoid.

Example: What is the area of a trapezoid in Figure 1-19 whose bases are 14 inches and 10 inches, and whose height (or altitude) is 6 inches? First, substitute the known values in the formula.

Figure 1-19. Trapezoid, with dimensions.

Figure 1-19. Trapezoid, with dimensions.