Reflection: Developing a Conceptual Understanding Time for Triangles - Section 3: Exploration #2 and Proof of Triangle Sum Theorem


In this lesson, I found that my students really struggled to identify the concepts of a side of a triangle being a transversal (cutting through 2 parallel lines).  When I drew in the parallel lines and transversal, I extended these lines, similar to Time for Triangles example so that students could see more clearly the relationship between the lines and angles. I think this really helped my students to understand how to prove that the sum of the interior angles in a triangle is 180 degrees. 

  Developing a Conceptual Understanding: Using Transversal and Parallel Lines
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Time for Triangles

Unit 4: Tremendous Triangles
Lesson 1 of 10

Objective: SWBAT identify key types of triangles when given angles and sides, and will prove number of degrees in a triangle.

Big Idea: Students will measure, cut and measure again to learn and prove key properties of triangles

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