Sunday, March 22, 2015

Measuring Angles with Protractors

We are finishing out our geometry unit by using protractors to determine the measurement of angles. We have really been having fun with protractors!

Here is a website that will walk you through the steps if you need a refresher: Use-a-Protractor

Kiddos will also need to be able to determine the degree without having a ray line up with the zero line. To do this, you need to skip count from one ray to the other to see the rotation degree. The angle below would measure at about 125 degrees.

Image result for steps to using a protractor

They will also need to be able to draw an angle using a protractor.

Finding the missing angle is also a concept we have worked on. Angle COA is a straight angle and therefore measures 180 degrees. We know that angle BOA measures 44 degrees. We can subtract the known angle from the large angle to determine the missing angle (180 - 44 = 136). Angle COB would measure 136 degrees.

Image result for missing angle in adjacent angles

Here are some games where kiddos can practice using a protractor:

Homework this week will have students drawing angles to a given degree and reading a protractor to determine the degree. It will be due on 3/30. Please let me know if you have any questions!

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