Five angles of a hexagon have measures 100°, 110°, 120°, 130°, and 140°.

Question

What is the measure of the sixth angle? 

Answer 1

The angles are 100^o, 110^o, 120^o, 130^o and 140^o

Let remaining angle = x.

In a hexagon number of sides n = 6

Sum of interior angles = (6 - 2)180^o

= 720^o

x + 100^o + 110^o + 120^o + 130^o + 140^o = 720^o

x + 600^o = 720^o

x = 720^o - 600^o

x = 120^o

Measure of sixth angle is 120^o .