Classifying Quadrilaterals – Similarities

Mat: Classifying Quadrilaterals

Grade Guidance: Grades 3–5; increase the depth of classification with readiness.

Focus: Compare quadrilaterals using shared and different attributes.

Try the Activity:

1. Examine the shapes on the mat. Identify the shared attribute: every quadrilateral has four straight sides forming a closed figure.
2. Compare two figures using side lengths, parallel sides, and right angles. Use printed markings rather than appearance alone.
3. Explain why squares are also rectangles: they have four right angles. A square additionally has four equal-length sides.
4. Record one similarity and one difference between two selected shapes.

Worked Example: A square and a nonsquare rectangle both have four right angles; the nonsquare rectangle does not have all four side lengths equal.

Quick Check: Does rotating a rectangle change its category? No; its attributes remain the same.

Adapt: Use a vocabulary bank and point to attributes. Extend by classifying a square as a rectangle, rhombus, and parallelogram.

Reflect: Choose a classroom use and one question that will reveal student understanding. Invite students to explain the movement and record an equation, diagram, or sentence.