Khan Academy
Khan Academy: Geometry: Triangle Angle Example 3
Explains how to solve for multiple missing angles in a diagram composed of multiple triangles using the triangle sum theorem and other angle relationships. This video also appears in the Geometry: Triangles strand. [5:42]
Khan Academy
Khan Academy: Geometry: Angle Game (Part 2)
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem. Continuation of Angle Game video. [9:49]
Khan Academy
Khan Academy: Geometry: The Angle Game
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem. [9:01]
Khan Academy
Khan Academy: Geometry: Proof Sum of Measures of Angles in a Triangle Are 180
Proof that the sum of the angles in a triangle is 180 using the relationship of angles formed when parallel lines are cut by a transversal. This video also appears in the Geometry: Triangles strand. [6:31]
Khan Academy
Khan Academy: Geometry: Ca Geometry: Deducing Angle Measures
Demonstrates how to solve five different problems from a released California Geometry state test that involve finding the measures of angles in different polygons. This video also appears in the Geometry: Worked Examples section. [10:58]
Khan Academy
Khan Academy: Geometry: Figuring Out All Angles for Congruent Triangles Example
Explains how to use given triangle congruency statements to determine the unknown measures of all angles in a diagram where one large triangle is divided into three congruent triangles. [4:35]
Khan Academy
Khan Academy: Geometry: Equilateral and Isosceles Example Problems
Demonstrates how to use the triangle sum theorem, properties of equilateral and isosceles triangles, and special angle pairs to determine the unknown measures of angles in three different diagrams. [6:27]
Khan Academy
Khan Academy: Geometry: Example Involving Isosceles Triangle and Parallel Lines
Demonstrates how to use the triangle sum theorem, properties of isosceles triangles, and special angle pairs formed when parallel lines are cut by a transversal to set up an equation using given algebraic expressions for angle measures...
Khan Academy
Khan Academy: Geometry: Another Isosceles Example Problem
Explains how to use given algebraic expressions for the measures of angles in an isosceles triangle and apply knowledge of the triangle sum theorem and the knowledge that the base angles of an isosceles triangle are congruent to...
Virtual Nerd
Virtual Nerd: What Is the Triangle Sum Theorem?
Watch this tutorial to learn about the Triangle Sum theorem which is useful in finding interior angle measurements. [4:48]
CK-12 Foundation
Ck 12: Elem Math: Overview Sum of the Angles of a Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on funding the sum of angles in a triangle.
CK-12 Foundation
Ck 12: Elem Math: Overview of Special Triangles
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on how to find missing angles in triangles.
Khan Academy
Khan Academy: Triangles: Triangle Angle Example 3
Explains how to solve for multiple missing angles in a diagram composed of multiple triangles using the triangle sum theorem and other angle relationships.
Khan Academy
Khan Academy: Sal's Old Angle Videos: Angle Game (Part 2)
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem.
Khan Academy
Khan Academy: Sal's Old Angle Videos: The Angle Game
Solving for unknown angle measures using knowledge of different angle relationships and the triangle sum theorem.
Khan Academy
Khan Academy: Triangles: Proof Sum of Measures of Angles in a Triangle Are 180
Video proving that the sum of the measures of the angles in a triangle are 180.
Math Mammoth
Math Mammoth: Angles in a Triangle Add Up to 180 Degrees: Exercises and Proof
Demonstrates how to solve problems where one angle of a triangle is unknown and how to draw an isosceles triangle with the given properties. This is followed by a proof of the angle-sum theorem. [9:18]
Khan Academy
Khan Academy: Geometry: Finding More Angles
Solving for measures of the angles in a triangle using algebra, the triangle sum theorem, and properties of angles created by a transversal that cuts parallel lines. [6:05]
Khan Academy
Khan Academy: Geometry: Triangle Angle Example 2
Shows how to find the measure of missing angles using the triangle sum theorem and vertical angles. This video also appears in the Geometry: Triangles strand. [4:55]
Khan Academy
Khan Academy: Geometry: Triangle Angle Example 1
Explains how to use the triangle sum theorem to solve for missing angle measures in a triangle. Also addresses the relationship between the measure of an exterior angle of a triangle and the measures of the remote interior angles. This...
Khan Academy
Khan Academy: Triangles: Triangle Angle Example 1
Explains how to use the triangle sum theorem to solve for missing angle measures in a triangle. A little about exterior angles being the sum of the remote interior angles. Also shows the relationship between the measure of an exterior...
Khan Academy
Khan Academy: Triangle Angle Properties: Sum of Interior Angles of a Polygon
Students explore the interior angles of a polygon by explanding on the concept that a triangle has 180 degrees and developing a formula for all polygons.
Khan Academy
Khan Academy: Example Involving an Isosceles Triangle and Parallel Lines
This video demonstrates how to use the triangle sum theorem, properties of isosceles triangles, and special angle pairs formed when parallel lines are cut by a transversal to set up an equation using given algebraic expressions for angle...
Khan Academy
Khan Academy: Triangles: Triangle Angle Example 2
Shows how to find the measure of missing angles using the triangle sum theorem and vertical angles.