This page shows how to construct (draw) a 60 degree angle with compass and straightedge or ruler. This construction works by creating an equilateral triangle. Recall that an equilateral triangle has all three interior angles 60°. We use one of those angles to get the desired 60 degree result. See the proof below for more details.
The above animation is available as a printable step-by-step instruction sheet, which can be used for making handouts or when a computer is not available.
This construction works by creating an equilateral triangle. Recall that an equilateral triangle has all three interior angles 60°. The image below is the final drawing above with the red items added.
Argument | Reason | |
---|---|---|
1 | Line segments AB, PB, PA are congruent | All drawn with the same compass width. |
2 | Triangle APB is an equilateral triangle | Equilateral triangles are those with all three sides the same length. |
3 | Angle APB has a measure of 60° | All three interior angles of an equilateral triangle have a measure of 60°. See Equilateral triangle definition |