Measure an angle by making your own angle measurer or protractor using the following steps.

1. Cut out a circular piece of waxed or other lightweight paper. (You may want to trace the bottom of a large cup.)

2. Fold the circle in half, and then fold the result in half.

3. Unfold the paper and open the circle. You should see four right angles at the center of the circle. Each right angle has measure 90.

4. Refold the circle on the same crease marks. Then fold the paper in half one more time. Unfold the paper to reveal eight angles, each of which measures 45.

5. Refold the paper on the previous creases. Then fold in half one more time. How large is each new angle? Label each new angle with the appropriate measure.

6. To measure an angle with your protractor, place the center of the circle on the point of the angle and line up one of the creases with a side of the angle. Estimate the angle's measure by finding where the other side aligns on the protractor.