2.B: Other Triangle Properties

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Jan 11, 2020
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- 2.A: Proving Triangle Congruence
- 2.C: Bisectors, Medians, and Altitudes

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Overview

The purpose of this lesson is to identify and use other triangle properties.

This lesson will address the following CCRS Standard(s) for Geometry:

8.G.5: Use informal arguments to establish facts about the angle sum and exterior angles of triangles, above 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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Go to http://wamap.org and log into our course to complete assignment 2.B with 80% or better.

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Other Triangle Properties [11:14]

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Complete assignment 2.B with 80% or better at http://wamap.org

Summary

In this lesson we have learned:

Isosceles triangles have two congruent sides and two congruent angles
The sum of the angles of a triangle is 180⁰
The exterior angle of a triangle is equal to the sum of the opposite two angles
When combined, the two shortest sides of a triangle are longer than the third (longest) side

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