Grade 4 · Math · Lesson 30

Use Protractors for Angles

An angle is formed where two rays meet at a point called the vertex. We measure angles in degrees (°) using a tool called a protractor. The size of the angle tells us how far one ray has turned from the other.

What this lesson teaches

1Identify acute, right, obtuse, and straight angles
2Measure angles using a protractor
3Classify angles as less than, equal to, or greater than 90°

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