Measuring Angles on a Circle
Instructions
Step 1. Experiment
Use the MOVE tool 
to drag Point C around the circle and change the size of angle DAC. The angle is colored in yellow. Experiment a bit.
Step 2. Estimate
Use the MOVE tool to turn off the Angle Reporter. Using estimation skills, try to make the various angles shown in the Report Table below. After each estimate, turn on the Angle Reporter and check your estimate. Record the actual angle measurement in a Report Table.
Report Table
Step 3. Play a Game (2 players)
With the Angle Reporter turned off, one person sets the angle to any desired size.
The other person then estimates the size of the angle in degrees.
If the estimate is within 10 degrees above or below the actual measurement, the estimator gets 5 points.
If the estimate is within 5 degrees above or below the actual measurement, the estimator gets 10 points.
Taking turns being estimator, play 5 rounds for high score.
to drag Point C around the circle and change the size of angle DAC. The angle is colored in yellow. Experiment a bit.
Step 2. Estimate
Use the MOVE tool to turn off the Angle Reporter. Using estimation skills, try to make the various angles shown in the Report Table below. After each estimate, turn on the Angle Reporter and check your estimate. Record the actual angle measurement in a Report Table.
Report Table
| Target Angle | Actual Angle |
| 45 degrees | degrees |
| 270 degrees | degrees |
| 90 degrees | degrees |
| 225 degrees | degrees |
| 180 degrees | degrees |