Using a Protractor (Measuring Angles)

Lesson Objective
In this lesson, we will learn how to measure angles using a protractor.
In this lesson, we will:
1. Learn what is a protractor. The following picture shows the parts of a protractor.

2. Learn how to use a protractor to measure angles that are:

1. Less than 180° (1st math video)
2. Greater than 180° (2nd math video)
The study tips and math videos below will explain more.

Study Tips

Tip #1
It is important to ensure the following when using a protractor:
1. The protractor's origin is at the vertex of an angle.

2. The protractor's base line is along the arm.

3. Make sure that you are using the appropriate scale when reading the angle. For example, the angle below is 50° and not 130°:

The math videos below will explain more on this.

Math Video

Video on parts of a protractor & measuring angles that are <180°
Video on measuring angles that are >180° using a protractor
Math Video Transcript

Practice Questions & More

Multiple Choice Questions (MCQ)
Now, let's try some MCQ questions to understand this lesson better.

You can start by going through the series of questions on using a protractor or pick your choice of question below.
1. Question 1 on measuring an angle that is lesser than 180°
2. Question 2 on measuring an angle that is greater than 180°
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