If two sides and the angle between them of one triangle are equal to the corresponding sides and angle between them of another triangle, then the two triangles are congruent. [br][br]In this activity, you will have to copy an angle. You can copy an angle in dynamic geometry using the compass tool, but it is a bit more complicated than copying a segment.[br][br]Watch this YouTube clip: http://www.youtube.com/watch?v=qngWUFgyyHc if you did not already. It gives a clear view of one way to use GeoGebra to copy an angle using tools that are equivalent to traditional geometry construction with a physical straightedge (for making line segments) and compass (for making circles).