Lesson objective: Measure angles to whole number degrees using a protractor.

This lesson helps to build procedural skill with measuring angles. A protractor is used here because it is a tool for measuring angles. This work develops students' understanding that an angle that turns through n one-degree angles is said to have a measure of n degrees.

Students engage in Mathematical Practice 5 (Use appropriate tools strategically) as they use a protractor to measure angles.

**Key vocabulary:**

- acute angle
- angle
- measure
- obtuse angle
- point
- protractor
- ray
- right angle
- vertex

**Special materials needed:**

- AngLegs (optional)
- protractor
- ruler