Calculate area, perimeter and median of a trapezoid from its parallel sides and height.
A trapezoid (trapezium in British English) has one pair of parallel sides. Its area is the average of the parallel sides times the height. The median is the segment connecting the midpoints of the legs.
Area
A = ½(a + b) × h
A right trapezoid has two adjacent right angles — one leg is perpendicular to both parallel sides.
The median (midsegment) connects the midpoints of the non-parallel sides and equals the average of the parallel sides.