Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...

In this triangle theorems worksheet, students identify the theorem used to prove the specified triangular relationship. Students are shown an illustration of two or more triangles. They identify the postulate that would be used to prove...

In this triangle congruence instructional activity, students select the postulate that is being illustrated to prove congruence between triangles. The instructional activity is self-scoring. Once students select the "check your work"...

I'd like to prove that this activity has a lot to offer. Seven problems using triangles and parallelograms practice the traditional method of a two-column proof. After the activity is some practice problems that show worked out...

In this triangle congruence worksheet, students review 4 triangle congruence properties and 4 examples. Students are then prompted to complete 15 problems analyzing whether two triangles are congruent and determine by which property.

Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...