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Triangles Bundle for High School Geometry

Math Giraffe
Grade Levels
9th - 11th
Formats Included
  • Zip
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Triangle Theorems & Properties, Congruent Triangles, Centers of Triangles, Triangle Proofs, & more!

Save money by getting eleven sets of resources in one bundle! These activities will help your students with triangles (from Triangle Sum Theorem all the way through to CPCTC proofs!)

(For an even bigger bundle that includes logic, proof, quadrilaterals, and more, try High School Geometry Super Bundle)

The zip file contains the following resources (all in PDF format):

1. Triangle Sum Theorem Inquiry Activity Lesson Pack

2. Exterior Angles Inquiry Activity

3. Classifying Triangles and Impossible Triangles (Always, Sometimes, Never Activity)

4. Congruent Triangles Activity

5. Congruent Triangles Proofs Worksheet Set

6. CPCTC Proofs Worksheet Set

7. Angle Puzzles: Angles in a Triangle

8. Similar Triangles Proofs Worksheet Set

9. Triangles Card Sort

10. Triangle Inequality Theorem Discovery

11. Centers of a Triangle "Doodle Notes"

12. Similar Triangles "Doodle Notes"

Take a look at the individual resources using the links below or the preview file.

Triangle Sum Theorem Inquiry Activity

Exterior Angles Inquiry Activity

Triangle Classification and Impossible Triangles

Congruent Triangles

Congruent Triangles Proofs

CPCTC Proofs

Angle Puzzles: Angles in a Triangle

Similar Triangles Proofs

Triangles Card Sort

Discovering Triangle Inequality Theorem

Centers of a Triangle Doodle Notes

Similar Triangles Doodle Notes

Total Pages
Answer Key
Teaching Duration
1 month
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to see state-specific standards (only available in the US).
Use congruence and similarity criteria for triangles to solve problems and to prove relationships in geometric figures.
Prove theorems about triangles.
Use the properties of similarity transformations to establish the AA criterion for two triangles to be similar.
Prove theorems about triangles.
Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so.


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