Section 5 - 5 The Triangle Inequality

Identify Possible Triangles Given Side Lenghts

Check each inequality, are ~S1 + S2 > S3 ~S2 + S3 > S1 ~S1 + S3 > S2 all true, if they are then a triangle can be made, if one or more are false a triangle cannot be made

Triangle Inequality Theorem

The sum of any two side lengths of a triangle is greater than the third side length.

Find range for the measure of the third side of a triangle

x must be less than the sum of the two sides, and greater than the difference of the larger side minus the smaller side