Paritian

Mathematics

Trapezoid Area Calculator

Area of a trapezoid from its two parallel sides and its height.

Results

Area 19.5 m²
The shape, to scale
Trapezoid Area CalculatorTrapezoid Area Calculator: b = 5.00 m, a = 8.00 m, h = 3.00 ma = 8.00 mb = 5.00 mh = 3.00 m

What this tool does

A trapezoid is the shape of a road cross-section, a drainage ditch and many irregular plots of land. Averaging the two parallel sides turns it into an equivalent rectangle, which is why the formula looks the way it does.

Formula

A = (a + b) ÷ 2 × h

Variables

SymbolMeaningUnit
aLonger basem
bShorter basem
hHeightm
AAream²

Worked example

  • Longer base8 m
  • Shorter base5 m
  • Height3 m
  • Area19.5 m²

Limitations

  • Mixing units is the most common source of error. Convert every input to the units shown next to each field before calculating.