Grade 1 · Math · Lesson 18

Properties of 2D Shapes — Sides and Corners

Last lesson we learned the names of 2D shapes. Now let's look more closely — what makes each shape different? The answer is in the sides and corners!

What this lesson teaches

1Count the sides and corners of a 2D shape
2Use sides and corners to sort and classify shapes
3Recognize that number of sides equals number of corners

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