Post on 26-May-2015
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