Triangle Inequalities, Exterior Angle Theorem and Hinge Theorem
Triangle Theorems Triangle Inequalities, Hinge Theorem, Exterior Angle Theorem
In this lesson, I will talk about triangle inequalities, exterior angle, and hinge theorem. These theorems can help us arrange the sides and angles of a triangle from smallest to largest.
What is the triangle inequality theorem?
This states that the sum of the lengths of any two sides of a triangle is greater than the length of the third side.
If one side of a triangle is longer than a second side, then the angle opposite the first side is larger than the angle opposite the second side.
If one angle of a triangle is larger than a second angle, then the side opposite the first angle is longer than the side opposite the second angle.
What is the Exterior Angle Theorem?
The measure of an exterior angle is equal to the sum of two remote interior angle.
What is the Hinge Theorem
If two triangles have two sets of congruent sides, the larger included angle will have the longer third side.
Useful Resources
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