Polygon Inequality Postulate works upon the inequality relationship in two polygons i.e. the triangle and the quadrilateral.

**Triangle Inequality Postulate:** The Triangle Inequality Postulate states that the sum of the lengths of two sides of any triangle is greater than the length of the third side.

For the above triangle:

*a + b > c *

b + c > a

a + c > b

**Quadrilateral Inequality Postulate:** the Quadrilateral Inequality Postulate states that the sum of the lengths of 3 sides of any quadrilateral is greater than the length of the fourth side.