Question

In the figure above, angles are as marked. The angle labeled with a measure of bº is an exterior angle. What is the measure of b?

Answer 1

105

Explanation:

First, solve for a

2a-15+2a+15+3a-5+a+5=360(Sum of interior angles of quadrilateral is 1360)

8a=360

a=360/8

a=45

Now,Look at the angles formed in straight line

b+2a-15=180(Sum of angles formed in a straight line is 180)

b+2×45=180+15

b=195-90

b=105