Trapezoid Area Calculator
Area of a trapezoid from its two bases and height.
How it works
Area = (a + b) ÷ 2 × h
"Average of the bases times height." A parallelogram (a = b) is a special case.
Worked example
Top base 4, bottom 8, height 5: S = (4+8) ÷ 2 × 5 = 30.
Notes and limitations
Area = average of the bases × height. Height is the perpendicular distance between bases; if you are given a slant side, find the height first.