This resource has been contributed by Winpossible, and can also be accessed on their website by clicking here - Triangle Inequality.

This mini-lesson, with the help of some examples, worked solution and using video explanation describes the triangle inequality theorem and angle-side relationship. The triangle inequality theorem states that the sum of the lengths of any two sides of a triangle is greater than the length of the third sides. E.g. In triangle*ABC*, *a*, *b*, and *c* are the sides corresponding to their angles, then:

a + b < c

b + c < a

c + a < b

You will further learn with examples and explanation, that side opposite to the smallest angle is the smallest side i.e. in triangle ABC, if m*A* < m*B* < m*C* , then a < b < c. For example, in triangle ABC, m*A* = 30° and m*B* = 50°, then the third angle is calculated by angle-sum theorem, which works out to 100°, (30° + 50° + m*C* = 180°, which gives m*C* = 100°). Therefore, longest side is opposite to the largest angle m*C*.

This mini-lesson, with the help of some examples, worked solution and using video explanation describes the triangle inequality theorem and angle-side relationship. The triangle inequality theorem states that the sum of the lengths of any two sides of a triangle is greater than the length of the third sides. E.g. In triangle

a + b < c

b + c < a

c + a < b

You will further learn with examples and explanation, that side opposite to the smallest angle is the smallest side i.e. in triangle ABC, if m

This FREE mini-lesson is a part of Winpossible's online course that covers all topics within Geometry. Click on the video below to go through it. If you like it, you can buy our online course in Geometry by clicking here.

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