#### DESCRIPTION:

This video gives us a walkthrough of the proof that the angle measures of the angles of a triangle add up to 180. This proof requires us to draw in a line on our own (specifically, one that is parallel to one side of the triangle, but it could be any side). Then we can treat the two non-parallel sides as transversals.

#### OVERVIEW:

Proving the Sum of Measures of Angles in a Triangle are 180 is a free educational video by Khan Academy.It helps students in grades 9,10,11,12 practice the following standards HSG.CO.C.10.

This page not only allows students and teachers view Proving the Sum of Measures of Angles in a Triangle are 180 but also find engaging Sample Questions, Apps, Pins, Worksheets, Books related to the following topics.

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1. HSG.CO.C.10 :** Prove theorems about triangles. Theorems include: measures of interior angles of a triangle sum to 180°; base angles of isosceles triangles are congruent; the segment joining midpoints of two sides of a triangle is parallel to the third side and half the length; the medians of a triangle meet at a point..

GRADES:

**9101112**

STANDARDS:

**HSG.CO.C.10**