A Pattern of Four Triangles

This Instructional Activity is a part of the Lesson 8, Unit 1, Grade 8. In this activity, several rigid transformations of the triangle form an interesting pattern. Triangle ABC can be mapped to each of the three other triangles in the pattern with a single rotation. As students work on the first three questions, watch for any students who see that a single rotation can take triangle ABC to CDE. The center for the rotation is not drawn in the diagram: it is the intersection of segment AE and segment CG.