Trapezoid Calculator
Calculate trapezoid area, entered perimeter and midsegment from bases, height and side lengths.
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Calculate a trapezoid from its parallel bases
Enter the two parallel base lengths, perpendicular height and the two remaining sides. The calculator returns area, the perimeter implied by all four entered sides and the midsegment length. Separating the height from slanted side lengths helps prevent a common mistake in which a leg is used as though it were perpendicular to the bases.
Check that the five measurements can coexist
Positive numbers alone do not guarantee that the side lengths, base difference and height describe a physically possible trapezoid. Confirm the diagram and measurements before using the perimeter for fabrication or purchasing. All lengths must use one unit, area uses the matching square unit, and allowances for cutting or assembly should be applied after the geometry is validated.
Frequently asked questions
Which sides are the bases?
The bases are the two sides that are parallel to each other.
Is a slanted side the height?
No. Height is measured perpendicular to the parallel bases.
What is the midsegment?
It is the segment halfway between the bases and equals their average length.