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Worksheet
Curated OER

Congruent Triangles

For Students 10th
In this congruent triangles worksheet, 10th graders solve and complete 16 different types of problems. First, they name the corresponding parts of the congruent triangles shown and draw a picture. Then, students list the five ways to...
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Lesson Plan
Virginia Department of Education

Congruent Triangles

For Teachers 9th - 11th Standards
Is this enough to show the two triangles are congruent? Small groups work through different combinations of constructing triangles from congruent parts to determine which combinations create only congruent triangles. Participants use the...
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Lesson Plan
EngageNY

Definition of Congruence and Some Basic Properties

For Students 8th Standards
Build a definition of congruence from an understanding of rigid transformations. The lesson asks pupils to explain congruence through a series of transformations. Properties of congruence emerge as they make comparisons to these...
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Unit Plan
Curated OER

Transformations in the Coordinate Plane

For Teachers 9th - 12th Standards
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...
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Worksheet
Curated OER

Geometry Practice: G.G. 28 #2: Triangle Congruence

For Students 10th - 12th
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 problems.  Answers are...
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Lesson Plan
Curated OER

Exploring Characteristics Needed to Prove Two Trianlges Congruent

For Teachers 10th
Tenth graders explore congruent triangles.  In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent.  The lesson combines dry erase board activities and the use of technology.
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Lesson Plan
Curated OER

Congruent Triangles Postulates

For Teachers 3rd - 4th
Students discover three lettered postulates that prove triangles congruent.
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Worksheet
Curated OER

Triangle Congruence

For Students 10th
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...
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Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve and complete 7 different problems. First, they list five ways to prove triangles congruent. Then, students name the method proving the triangles congruent in each problem.
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Worksheet
Curated OER

Triangles and Congruence

For Students 8th - 10th
Can your class construct triangles and determine congruence? Find out with this well put together worksheet. THey construct triangles to given specifications and identify if they are congruent. There are 3 muti-step problems to solve.
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Worksheet
Curated OER

Congruent Triangles

For Students 10th
In this congruent triangles worksheet, 10th graders solve and complete 10 different problems to determine whether each set of triangles is congruent or not. First, they copy each diagram onto a piece of paper and mark up the paper with...
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Lesson Plan
EngageNY

Base Angles of Isosceles Triangles

For Students 9th - 10th Standards
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...
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Lesson Plan
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...
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Activity
Illustrative Mathematics

Congruent Triangles

For Teachers 7th - 9th Standards
Geometers prove that triangle PQR is congruent to triangle ABC by describing any combination of rotations, reflections, and translations that would prove it so. There is only this single task on the handout, but a detailed explanation of...
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Worksheet
Curated OER

Proving Figures Congruent

For Students 10th
In this proving figures congruent worksheet, 10th graders solve and complete 11 different problems. First, they determine the additional information needed to prove the triangles congruent. Then, students determine which postulate, if...
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Worksheet
Curated OER

Proofs

For Students 8th - 11th
In this geometric proof worksheet, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use given...
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Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
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...
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Handout
Mt. San Antonio Collage

Congruent Triangles Applications

For Students 9th - 12th Standards
Triangles are all about threes, and practicing proving postulates is a great way to get started. The first page of the worksheet provides a brief introduction of the different properties and postulates. The remaining pages contain...
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Lesson Plan
EngageNY

More on the Angles of a Triangle

For Students 8th Standards
Angles and triangles: they're all connected. Uncover the connections between angles in triangles. Scholars learn how to find both exterior and interior angle measures in triangles. The lesson emphasizes the vocabulary related to these...
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Lesson Plan
West Contra Costa Unified School District

Investigating Special Right Triangles

For Teachers 9th - 12th
Scholars first investigate relationships in the side lengths of 30°-60°-90° triangles and 45°-45°-90° triangles. This knowledge then helps them solve problems later in the lesson plan about special right triangles.
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Lesson Plan
Curated OER

The Truth About Triangles And Proofs

For Teachers 9th - 12th
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...
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Lesson Plan
EngageNY

Law of Sines

For Teachers 11th - 12th Standards
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...
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Activity
Illustrative Mathematics

Points equidistant from two points in the plane

For Teachers 9th - 12th Standards
Young geometers apply their deductive reasoning skills and knowledge of proving triangles congruent in a task that asks them to prove if a point lies on the perpendicular bisector of a segment, then it is equidistant from the endpoints...
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Performance
Radford University

Triangles in Parallelograms

For Teachers 9th - 12th Standards
What's the point of looking at triangles when trying to draw parallelograms? Given three non-collinear points, pupils determine and justify all possible points that would create a parallelogram. They then analyze the four triangles that...