How can you prove it? Guide classes through an exploration of two possible triangle congruence criteria: AAS and HL. Learners connect this criteria to those previous learned and also explore criteria that does not work. The lesson...

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...

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,...

Students 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...

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...

In this geometry worksheet, 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.

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...

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

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...

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...

Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...

Students differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.

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...

Tenth graders explore congruent triangles.  In this geometry instructional activity, 10th graders investigate the conditions necessary to prove two triangles are congruent by SSS, ASA, AAS, or SAS. 

In this triangle congruence worksheet, 10th graders solve 12 different problems that include determining triangle congruence. First, they prove that triangles are either congruent or similar. Then, students determine whether they can...

Students engage in a lesson that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the importance of...

In this congruent triangles worksheet, students 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 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.

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

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...

Your learners will make good use of the Socratic method in a collaborative task that begins with an assumed solution and ends with deeper understanding of the idea of determining two triangles congruent.

Combine transformations and triangle congruence in a single lesson. Scholars learn to view congruent triangles as a rigid transformation. Using triangle congruence criteria, learners identify congruent triangles and the rigid...

In this triangle theorems instructional activity, 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...

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