Math 6: GeometryInvestigating Angles

Different types of angles Label degrees:

How to Use a Protractor

How to carefully place and read the protractor

Protractor = tool to measure an angle

Parts of a Protractor

Vocabulary Words

Measuring an Angle

Step 1: Determine if the type of angle. Eg. Acute or obtuse

Step 2: Place the center mark of the protractor on the vertex of the angle

Step 3: Rotate the Zero-edge of the protractor to line up with one ray of the angle and for the other ray of the angle to cross the protractor’s scale

Step 4: Read the measure of the angle of the ray that crosses the protractor’s scale

Common Mistakes

1) Using the incorrect scale

2) The centre mark is not on the vertex. (This usually happens after rotating the protractor.

3) Counting the marks in the wrong direction. Pay attention to whether these numbers are increasing or decreasing.

How to Measure Angles

Master 3.6

Measure angles

In Class Work

pg. 84 – 85 # 1, 2, and 4

Homework

pg. 34 + 35