Classifying quadrilaterals (5th grade math)

Quadrilaterals are primarily classified, not by their angles, nor by their sides, but by the presence or absence of parallel sides. In this lesson, we sort a bunch of quadrilaterals in bins, based on whether they have no parallel sides, one pair of parallel sides, or two pairs of parallel sides. Then lastly, we also look at some questions, such as is every trapezoid a parallelogram.

In this lesson, we go through definitions of the various quadrilaterals and how we mark congruent sides and parallel sides in drawings. Then, we solve two problems. The latter asks you to draw a parallelogram with 5 cm and 8 cm sides. Can you draw several different kinds?

See also

Classify triangles — video lesson

Math Mammoth Geometry 1 — a self-teaching worktext with explanations & exercises (grades 4-5)

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