Trapezoid Calculator

What Is a Trapezoid?

A trapezoid is a quadrilateral with at least one pair of parallel sides called bases. The other two sides are legs. Key measurements include area, perimeter, height, median, and interior angles.

For specialized cases, try our Right Trapezoid Calculator, Isosceles Trapezoid Calculator, and Area of a Trapezoid Calculator.

Trapezoid Formulas

Area:

$$A = \frac{(a + b) \times h}{2}$$

Perimeter:

$$P = a + b + c + d$$

Median:

$$m = \frac{a + b}{2}$$

Height from a leg and angle: $h = c\sin(\alpha) = d\sin(\delta)$.

Worked Example

A right trapezoid has bases $a = 8$, $b = 5$, right leg $d = 3$, and $\delta = 45°$. Height $h = 3\sin(45°) \approx 2.12$, area $A \approx 13.79$, and perimeter $P \approx 18.12$.