Geometry construction using a compass and straightedge

Given an angle formed by two lines with a common vertex, this page shows how to construct another angle from it that has the same angle measure using a compass and straightedge or ruler. It works by creating two
congruent triangles.
A proof is shown below.

Click here for a printable worksheet containing two angle copying problems.
When you get to the page, use the browser print command to print as many as you wish. The printed output is not copyright.