## What’s Your Angle?

### Posted on : 12-05-2010 | By : InteractiveEducator | In : Geometry

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**The websites:**

These sites focus on two angles concepts: Estimating the size of an angle when given its measurement and estimating the measurement of an angle when shown its size.

**Classroom Applications:**

1. Begin by selecting Show the Angle. Use this application to explore the relative size of angles and to work together to establish “benchmark” angles to guide the estimation process. For example: Is the angle less than 90 degrees? Is the angle between 90 degrees and 180 degrees? Help your students to develop the concept of the size of ten degree increments.

2. Click Teacher Controls. Choose Make the Angle Game. Use this application to practice creating an angle to match the given measurement. Use a think aloud for the first problem. Answer the problem while explaining the reasoning behind your answer. For the next few questions, have students draw their angle estimations independently or in small groups. Then have them share the strategies they used to determine their estimations. Finally, choose one student to answer for the class. (You may want to skip the think aloud if you want students to come up with their own estimation strategies and not be influenced by your demonstration. Be sure to share and discuss the strategies as a whole class.)

3. Click Teacher Controls. Choose Estimating up to 90 or Estimating up to 180. Have the students estimate the angle measurement of the given angle individually or in groups. Have them explain their thought process. Then choose one student to answer for the class.

4. Click Teacher Controls. Choose Make and Measure. This could be used for a partner activity at a center or as a whole class activity by dividing the class into two different teams. Have the first team create an angle and measure it with the protractor while the second team is not watching. Then, have the second team guess the angle measurement and then measure the angle to check their accuracy. A few suggestions for game rules: The angles created must end in 5 or 0. Rarely will the students guess the measurement with 100% accuracy so a point system that allows for close answers works well. 3 points for 100% accuracy. 2 points if the estimation is within 5 degrees. 1 point if the estimation is within ten degrees.

The last two websites can be used as whole class practice, by groups during center time, or by individual students on computers at school and at home. The second website asks students to set the angle of a laser beam to destroy an alien spacecraft. It is a nice introductory activity since the angle measurements are in 10 degree increments. The third website asks students to help the monkey find the banana by creating an angle with the given measurement. This site is more challenging since all 360 degrees are used.