How to Identify a Trapezoid

By Damon Verial; Updated April 24, 2017

A trapezoid looks like a silly rectangle. Though it has four sides, two of its sides don’t “mirror” each other, making the shape appear a little lopsided. Because a trapezoid is by definition a quadrilateral, you can easily identify this shape by checking a few of its characteristics.

2 Parallel Sides

A trapezoid is a polygon with exactly two sides parallel to each other. Though it is like a rectangle, square or parallelogram, there are differences. The main difference is that a trapezoid has only one pair of parallel sides.

Trapezoid Checklist

First, ensure it has four sides. Next, see if it has any pairs of parallel sides. Look at one side and the side opposite of it. If the sides are parallel -- going in the same direction, like the opposite sides of a rectangle -- it is possible it is a trapezoid. Finally, check the other pair of sides. If they are not parallel -- that is, going off in different directions -- your shape is a trapezoid.

What a Trapezoid Is Not

A trapezoid cannot have fewer or more than four sides. It cannot have more than one pair of parallel sides. It cannot have more than two right angles.

About the Author

Having obtained a Master of Science in psychology in East Asia, Damon Verial has been applying his knowledge to related topics since 2010. Having written professionally since 2001, he has been featured in financial publications such as SafeHaven and the McMillian Portfolio. He also runs a financial newsletter at Stock Barometer.