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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Showing a Triangle Congruence: The General Case

For Teachers 9th - 10th Standards
Given distinct, congruent triangles, students are asked to show that congruence can always be shown with one, two, or three rigid motions. Aligns with G-CO.A.5.
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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Showing a Triangle Congruence: A Particular Case

For Teachers 9th - 10th Standards
Given two congruent triangles, students are asked to analyze the effects of different transformations. Aligns with G-CO.A.5.
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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.g, G Gpe, G Srt, G Co Is This a Rectangle?

For Teachers 9th - 10th Standards
For this task, students are given four sets of coordinate pairs and are asked to determine if they represent a rectangle. Aligns with 8.G.A, 8.G.B, G-CO.B, G-GPE.B, and G-SRT.B.5.
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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.g Triangle Congruence With Coordinates

For Teachers 8th Standards
For this task, 8th graders explore congruence and transformations of two triangles on a coordinate grid. Aligns with 8.G.A.2.
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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.g Congruent Triangles

For Teachers 8th Standards
In this task, 8th graders investigate congruence and transformations of two triangles on a coordinate grid. Includes a GeoGebra worksheet that the teacher can use for demonstration purposes. Aligns with 8.G.A.2.
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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 8.g Cutting a Rectangle Into Two Congruent Triangles

For Teachers 8th Standards
This task shows the congruence of two triangles formed by cutting a rectangle in half along the diagonal. Students are asked to investigate elements of congruence and transformations among the shapes. Aligns with 8.G.A.2.
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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Why Does Sss Work?

For Teachers 9th - 10th Standards
In this task, students must show that two triangles are congruent given a set of steps which produce a rigid transformation of the plane. Includes an experimental GeoGebra worksheet that instructors can use to demonstrate the task....
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Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Co Why Does Sas Work?

For Teachers 9th - 10th Standards
In this task, students must explain the given reasoning for why triangle ABC is congruent to triangle DEF using the language of reflections. Aligns with G-CO.B.8.
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Interactive
Math Open Reference

Math Open Reference: Congruence

For Students 9th - 10th Standards
A complete reference guide to congruence including congruent triangles and polygons. It provides definitions, animation, and interactive activities that enhance further explanation.
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Unit Plan
Math Open Reference

Math Open Reference: Triangles

For Students 9th - 10th Standards
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
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Activity
Analyze Math

Analyze Math: Congruent Triangle Examples

For Students 9th - 10th Standards
The geometry tutorial investigates congruent triangles. Students learn about the definitions and theorems on congruent triangles. Some topics included are angle-side-angle, side-side-side, and side-angle-side congruence postulates. The...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Congruent Triangles

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] In this lesson students determine whether two triangles are congruent. Students examine guided notes, review guided practice, watch instructional videos and attempt...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Congruent Triangles

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept teaches students what it means for two triangles to be congruent and how to identify corresponding parts of congruent triangles. Students examine guided...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Sss Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] Prove two triangles are congruent with the Side-Side-Side shortcut.
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Sas Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] Prove two triangles are congruent with the Side-Angle-Side shortcut.
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Handout
CK-12 Foundation

Ck 12: Geometry: Triangle Congruence Study Guide

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] Provides an overview of triangle congruence, including key terms, properties of congruent triangles, triangle postulates and theorems, and special triangles.
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Congruence Statements

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] In this lesson students deduce information about triangles with congruence statements. Students examine guided notes, review guided practice, watch instructional...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Comparing Angles and Sides in Triangles

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] In this lesson students compare sides and angles in triangles. Students examine guided notes, review guided practice, watch instructional videos and attempt practice...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Sas Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to the SAS Triangle Postulate and how to prove that two triangles are congruent given only information about two pairs of sides and...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Asa and Aas Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to the ASA and AAS Triangle Congruence shortcuts. Students examine guided notes, review guided practice, watch instructional videos...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Hl Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept introduces the HL Triangle Congruence shortcut in order to prove that two right triangles are congruent. Students work on mastering the skill by watch...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Sss Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept introduces students to the SSS Triangle Congruence Postulate and how to prove that two triangles are congruent given only information about their side...
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Unit Plan
CK-12 Foundation

Ck 12: Geometry: Asa and Aas Triangle Congruence

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] In this lesson students prove two triangles are congruent with the Angle-Side-Angle and Angle-Angle-Side shortcuts. Students examine guided notes, review guided...
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Unknown Type
Khan Academy

Khan Academy: Use Similar and Congruent Triangles

For Students 9th - 10th Standards
Solve geometry problems with various triangles by using all you know about similarity and congruence. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.