This page provides a list of educational videos related to Measures of Angles of a Triangle. You can also use this page to find sample questions, apps, worksheets, lessons , infographics and presentations related to Measures of Angles of a Triangle.

Proving the Sum of Measures of Angles in a Triangle are 180

By Khan Academy

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.

Geometry -- Lesson 4.3 -- Congruent Triangles

By MisterRutter

This geometry lesson explains congruent triangles: triangles with the same measure sides and angles.

Introduction to Geometry - 21 - Identifying Similar Triangles AA

By thenewboston

"AA" stands for "Angle-Angle." This means that if two triangles are known to have two corresponding angles that are equal in measure, then the two angles are similar.

7.1 Triangle Application Theorems (Lesson)

By AutenMath

A lesson explaining a.) why the sum of the measures of a triangle equals 180 degrees b.) the relationship between exterior angles and remote interior angles of a triangle and c.) the midline theorem

Find missing angles of triangles

By Khan Academy

Sal solves the following problem: The measures of two angles of an isosceles triangle are 3x+5 and x+16. Find all possible values of x.

15.2 Inequalities in a Triangle (Lesson)

By AutenMath

A lesson on the inequality theorems and relationships of side length and angle measures in a triangle

45-45-90 triangles | Right triangles and trigonometry | Geometry | Khan Academy

By Khan Academy

Video uses an electronic black board with different colored pens. Introduction to 45-45-90 Triangles, these can also be called right triangles because of the 90 degree measurement. These triangles are special because if two angles of a triangle are equal the one side they don’t share is going to be equal. This then goes on to explain Pythagorean Theorem, Side A squared + Side B squared = Side C squared, side C is the hypotenuse or the side that is shared in a triangle. The narrator goes on to explain how to solve, using square roots. This video is for middle school students.

Similar Triangles, Part 2 - Khan Academy

By Khan Academy

Video uses an electronic black board with different-colored pens. In this video. Mr. Khan discusses the measurement of alternate interior angles, corresponding angles and how they are similar. Triangles are drawn in two parallel lines and a transversal. Narrator shows how to figure out the length of the sides of the angles when three sides are known. Good quality video. Good for middle elementary and middle school students.

Similar Triangles, Part 2 - Khan Academy

By Khan Academy

Acute Triangle - YourTeacher.com - Geometry Help

By yourteachermathhelp

In this lesson students learn to classify triangles as acute (all angles acute) right (one angle right) or obtuse (one angle obtuse). Students also learn that the sum of the measures of the angles of a triangle is 180 degrees and students are asked to use this formula to find the measures of missing angles in given triangles.