Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence...

In this triangle congruence instructional activity, students state if triangles are congruent and if the congruence is based on side, side, side or the side, angle, side theorems in eighteen problems.  The solutions are found on the...

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...

Pupils identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.

Students will determine if triangles are congruent and state the appropriate congruence theorem. In this geometry lesson, students will determine what information is needed to determine if a pair of triangles are congruent using ASA,...

Learners investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, students discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by two rays...

In this congruent triangles worksheet, high schoolers solve four multiple choice problems. Students determine which statement is the appropriate reasoning to say that two triangles are congruent.

In this triangle congruence worksheet, students use SSS, ASA, AAS and HL to determine the congruence of triangles.  They identify the theorem that proves congruence.  This three-page worksheet contains 4 multi-step...

In this congruent triangles worksheet, 10th graders solve 5 various types of geometry problems related to triangles. First, they draw and label triangles, indicating the additional pairs of corresponding parts that would have to be...

Having a good working knowledge of math vocabulary is especially important for geometry learners. Here are 119 pages worth of wonderfully constructed definitions, constructions, formulas, properties, theorems, and postulates. This is a...

In this triangle similarity worksheet, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles shown are...

Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...

Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...

Students explore the concept of similarity and congruence. In this similarity and congruence lesson, students identify and verify whether or not two figures are similar, congruent, or neither. Students use postulates and theorems such as...

High schoolers explore the concept of similarity and congruence. In this similarity and congruence lesson, students cut out strips of paper and form a triangle. High schoolers try to prove that their triangles are congruent using the SSS...

In this geometry instructional activity, students identify the different ratios of triangles using the theorems. They use SSS, SAS, ASA and AAS to differentiate between triangles. There are 7 questions with an answer key.

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.

Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...

In this proving triangles congruent worksheet, 10th graders solve 5 different problems that include proofs and proving congruence in triangles. First, they determine which postulate can be used to prove the triangles congruent and mark...

Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This...

Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...

Learners investigate the relationship between angles and their sides. In this geometry instructional activity, students prove why SSA does not work as a true angle side relationship theorem.

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

In this properties of geometry worksheet, 10th graders solve and complete 12 different problems that include various theorems. First, they draw a figure that illustrates the SAS inequality property. Then, students prove that two line...