Now we are getting more advanced! You will now duplicate a given angle at a different location. To do this, you use triangle congruence properties. It is a fact that two triangles with three equal sides are congruent, and also have equal angles.

 

You see that angle at the point B? Create the same angle at B*

The trick is already visible in the construction. You need to construct congruent triangles ABC and A*B*C*. All sides must have the same lengths!

To get started, you will want to copy the length of one segment onto another line.

1. Click on the “Circle from 3 Points” tool Circle3. 
2. The click on points A and B.
3. Finally, click on point B*.

This will create a circle with radius AB and center B*.

Keep doing this for the other two segments to create a congruent triangle.

If you need a hint, the solution is here.

Continue