How do we use the triangle inequality theorem?

Triangle Inequality Theorem - The sum of any 2 sides of a triangle must be greater than the                measure of the third side. 

Ex:

A= 7, B= 10, C= 4

7 + 10 > 4

10 + 4 > 7

7 + 4 > 10

http://www.mathwarehouse.com/geometry/triangles/triangle-inequality-theorem-rule-explained.php