Curriculum / Math / 8th Grade / Unit 3: Transformations and Angle Relationships / Lesson 21

Transformations and Angle Relationships

Lesson 21

Math

Unit 3

8th Grade

Lesson 21 of 22

Objective

Define and use the exterior angle theorem for triangles.

Lesson Map

Topic A: Congruence and Rigid Transformations

Lesson

Understand rigid transformations that move figures and maintain congruency (translation, reflection, rotation).

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.2

Lesson

Describe and perform translations between congruent figures. Use translations to determine if figures are congruent.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.2

Lesson

Describe and apply properties of translations. Use coordinate points to represent relationships between translated figures.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.28.G.A.3

Lesson

Describe and perform reflections between congruent figures. Understand what features are preserved under reflections.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.2

Lesson

Describe sequences of transformations between figures using reflections and translations. Use coordinate points to represent relationships between reflected figures.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.28.G.A.3

Lesson

Describe and perform rotations between congruent figures.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.2

Lesson

Describe sequences of transformations between figures using rotations and other transformations.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.2

Lesson

Describe a sequence of rigid transformations that will map one figure onto another.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.2

Lesson

Describe multiple rigid transformations using coordinate points.

Standards

8.G.A.28.G.A.3

Lesson

Create patterns with congruent figures and use transformations to demonstrate the congruence between figures.

Standards

8.G.A.1.A8.G.A.1.B8.G.A.1.C8.G.A.28.G.A.3

Topic B: Similarity and Dilations

Lesson

Define a dilation as a non-rigid transformation, and perform dilations on points, line segments, and figures using scale factor.

Standards

8.G.A.4

Lesson

Describe and perform dilations.

Standards

8.G.A.4

Lesson

Describe a sequence of dilations and rigid motions to show similarity between figures.

Standards

8.G.A.4

Lesson

Describe the effects of dilations and rigid motions on figures using coordinate points.

Standards

8.G.A.38.G.A.4

Lesson

Use properties of similar figures to find missing side lengths and to determine scale factor between similar figures.

Standards

8.G.A.4

Lesson

Use properties of similar triangles to model and solve real-world problems.

Standards

8.G.A.4

Topic C: Angle Relationships

Lesson

Define and identify corresponding angles in parallel line diagrams. Review vertical, supplementary, and complementary angle relationships.

Standards

8.G.A.28.G.A.5

Lesson

Define and identify alternate interior and alternate exterior angles in parallel line diagrams. Find missing angles in parallel line diagrams.

Standards

8.G.A.28.G.A.5

Lesson

Solve for missing angle measures in parallel line diagrams using equations.

Standards

8.G.A.5

Lesson

Define and use the interior angle sum theorem for triangles.

Standards

8.G.A.5

Lesson

Define and use the exterior angle theorem for triangles.

Standards

8.G.A.5

Lesson

Define and use the angle-angle criterion for similar triangles.

Standards

8.G.A.5

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