Grade 4 · Math · Lesson 25

Identify Angles and Lines

An angle is formed when two lines or rays meet at a point called the vertex. We measure angles in degrees (°). The size of an angle tells us how wide or narrow it is. Lines can also be classified by how they relate to each other — whether they meet, cross, or never touch.

What this lesson teaches

1Identify and define acute, right, obtuse, and straight angles
2Classify angles by their size in degrees
3Identify parallel, perpendicular, and intersecting lines
4Recognize angles and lines in real-world shapes and objects

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