Question

In the figure, ∠4 is an exterior angle to AUL

(a) Explain why m∠4 is equal to the sum of the measures of the two nonadjacent interior angles.

(b) What is m∠4 ?

Answer 1

Check the picture below.

a)

180° - ∡3 = non-adjacent angles

and

180° - ∡3 = ∡4

b)

∡4 = sum of non-adjacent angles = 77°