This matching activity is a great way to have students practice finding unknown measures of interior and exterior angles of triangles. There are 12 problems students will solve and match up the answers to on the mat. Students need to apply the triangle sum theorem and also use supplementary and complementary angles to solve for the unknown measure. Teacher answer key included!
to see state-specific standards (only available in the US).
Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so.