Area of a trapezoid is calculated by multiplying the height by the sum of its bases then divide everything by 2.

A trapezoid has 2 of its opposite sides parallel. The parallel sides are called bases. One base is longer than the other. Both bases are perpendicular on the height.

A = [(b1 + b2) × h] ÷ 2

Where *A* is the area, *b1* is the longer base, *b2* is the shorter base, and *h* is the height.

Example:

If: b1 = 7; b2 = 5; h = 3

Then A = ?

A = [(b1 + b2) × h] ÷ 2 = [(7 + 5) × 3] ÷ 2 = (12 × 3) ÷ 2 = 36 ÷ 2 = 18 square units