Refine Your Results

Content Curators

Grades

Subjects

Resource Types

Standards

Now... gain access to over 2 Million curated educational videos and 500,000 educator reviews to free & open educational resources

Get a 10 Day Free Trial

110 resources with the concept geometric proofs

1 In 1 Collection
EngageNY

Comparing the Ratio Method with the Parallel Method

For Students 9th - 10th Standards
Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...
1 In 1 Collection
EngageNY

End-of-Module Assessment Task - Geometry (module 1)

For Students 9th - 10th Standards
Have you hit a wall when trying to create performance task questions? Several open-ended response questions require a deep level of thinking. Topics include triangle congruence, quadrilaterals, special segments, constructions, and...
1 In 1 Collection
EngageNY

Review of the Assumptions (part 2)

For Students 9th - 10th Standards
Is the amount of information getting overwhelming for your geometry classes? Use this strategy as a way to organize information. The resource provides a handout of information studied in relation to triangle congruence. It includes a...
1 In 1 Collection
EngageNY

Special Lines in Triangles (part 2)

For Teachers 9th - 10th Standards
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
1 In 1 Collection
EngageNY

Review of the Assumptions (part 1)

For Students 9th - 10th Standards
What was the property again? Tired of hearing this from your pupils? Use this table to organize properties studied and as a reference tool for individuals. Learners apply each property in the third column of the table to ensure their...
1 In 1 Collection
EngageNY

Triangle Congruency Proofs (part 2)

For Teachers 9th - 10th Standards
Looking to challenge your students that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs to...
1 In 1 Collection
EngageNY

Triangle Congruency Proofs (part 1)

For Teachers 9th - 10th Standards
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...
1 In 1 Collection
EngageNY

Congruence Criteria for Triangles—ASA and SSS

For Students 9th - 10th Standards
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
1 In 1 Collection
EngageNY

Congruence Criteria for Triangles—SAS

For Students 9th - 10th Standards
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 if...
1 In 1 Collection
EngageNY

Looking More Carefully at Parallel Lines

For Students 9th - 10th Standards
Can you prove it? Making assumptions in geometry is commonplace. This resource requires mathematicians to prove the parallel line postulate through constructions. Learners construct parallel lines with a 180-degree rotation and then...
1 In 1 Collection
Lesson Planet

Geometry Project

For Students 9th - 12th Standards
Proofs are usually an intimidating assignment. An engaging lesson focused on geometric proofs may reduce the anxiety! Pupils choose between several triangle proofs to complete and work on completing them. The assignment also gives a...
2 In 2 Collections
Lesson Planet

Postulates and Proofs: Let's take it to the courtroom!

For Students 9th - 10th Standards
Order in the court! Turn your geometry classroom into a courtroom and have your pupils defend their proofs. A fun and educational lesson allows both individual and group work with geometric proofs and group presentations in a court of...
Lesson Planet

Analytic Geometry Study Guide

For Students 9th - 12th Standards
Are you looking for a comprehensive review that addresses the Common Core standards for geometry? This is it! Instruction and practice problems built specifically for standards are included. The material includes geometry topics from...
2 In 2 Collections
Lesson Planet

Are They Similar?

For Teachers 9th - 11th Standards
Learners separate things that just appear similar from those that are actually similar. A diagram of triangles is given, and then a variety of geometric characteristics changed and the similarity of the triangles analyzed. Because the...
1 In 1 Collection
Lesson Planet

Similar Triangles

For Teachers 9th - 11th Standards
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...
2 In 2 Collections
Lesson Planet

Shortest Line Segment from a Point P to a Line L

For Teachers 9th - 11th Standards
One of the hardest skills for many young geometers to grasp is to move beyond just declaring obvious things true, and really returning to fundamental principles for proof. This brief exercise stretches those proving muscles as the class...
Lesson Planet

Accelerated Geometry Review Sheet

For Students 8th - 10th Standards
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
1 In 1 Collection
Lesson Planet

Vertical Angles Proof Samples

For Teachers 7th - 10th Standards
This visual, manipulative-based format for teaching geometric proofs nicely scafolds learners' development of mathematical reasoning and proof skills. This sample represents a proof of the congruence of vertical angles in four formats;...
Lesson Planet

The Parallelogram Law

For Teachers 9th - 12th Standards
Use your pupils' sense of curiosity to explore the Parallelogram Law. Here is an activity that outlines a complete instructional activity from beginning to end, allowing pupils to follow a conjecture through to the proof stage.
Lesson Planet

Semester 1 Review for Geometry final

For Students 10th
In this geometry worksheet, 10th graders solve problems that are based on the topics covered in a first semester geometry class, including, linear equations and the equations of parallel and perpendicular lines, the logic of geometry,...
Lesson Planet

Proving Quadrilateral Properties

For Teachers 9th - 11th
Working backwards can sometimes help you see a path to solving a problem. In this chapter, properites of quadrilaterials are proven by looking at flowcharts and working the probem backwards. Worked through examples are given, along with...
Lesson Planet

Proving Supplementary and Complementary

For Teachers 9th - 12th
Learners examine their prior knowledge of algebra to explore geometric proof. In this proving supplementary and complementary instructional activity, students prove a solution to an equation using algebraic properties. Learners then...
Lesson Planet

Geometry: Properties of Triangles

For Students 10th - 12th
In this properties of triangles instructional activity, students use their knowledge of triangles to find determine angle measurement. They use geometric theorems to prove equal angles. This three-page instructional activity contains 15...
Lesson Planet

Parallelograms

For Students 10th
In this parallelograms worksheet, 10th graders solve and measure 81 various types of problems that include parallelograms. First, they use the figure shown to solve each of the angle measurements listed. Then, students explain why other...