1. 9.3 – Measuring Angles
Grade 4

2. Protractor – a tool to measure angles
Mathematicians have a special tool to measure angles. This tool is called a protractor.
Each small unit on the protractor is called a degree.
How many degrees are in a right angle?

3. Measuring an Acute Angle

4. Measuring an Obtuse Angle

5. What kind of angles are these?

6. How do I measure an angle that looks like this?

7. Worksheet A
Look at Worksheet A. Using a protractor, measure the angles and write down if it’s an acute, obtuse, or a right angle.

8. Worksheet B
Using a protractor, draw an angle with the given measure. Write down whether it’s an acute, obtuse, or right angle.

9. Turn to Page 201
#25. Measure all of the angles created by the intersections of Main Street and Pleasant Street.
#26. If angle ABC is an obtuse angle, which of the following could NOT be its measure?

10. With a Partner
Draw an angle. Have your partner measure the angle and say the measurement. You measure the angle and tell them if it’s correct or not.

11. Homework
Pg. 200 (#7 – 22)