Construct a triangle given ASA

If you are given two angles and the included side of a triangle, you can construct the triangle as follows:

Given:  Side AB, and angles A and B, construct triangle ABC.

 

Solution:

First construct side AB by drawing a line slightly longer and marking off the right length using the compass:

Next copy angle A:

Finally, copy angle B.  Be sure to put the point of the compass at B when drawing the first arc.  The intersection of the copied sides of the angles is point C:

Here is an animation for this construction.

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