1.the illustration below shows two supplementary angles, ∠a and ∠b. the measure of ∠b is 110°. what is the measure of ∠a?

Supplementary angles = 180
 
angle A = 180 - angle B

angle A = 180 - 110

Angle A = 70 degrees

In the first triangle 80+20+p=180 (since sum of all angles of a triangle is 180)so p= 80also in second triangle 55+45+q=180 (since sum of all angles of a triangle is 180)so q=80so we can conclude that p=80 degrees q=80 degrees so p=q=80 degreeshence option b is correct