Mathematics

Problem

Lines

a

and

b

are parallel and are intersected by a transversal. At the intersection with line

a

, the exterior angle on the right side of the transversal measures

(7z + 20)^\circ

. The interior angle on the left side of the transversal at the intersection with line

b

measures

(3z + 50)^\circ

. Find the measure of this interior angle. a) 97

^\circ

b) 73

^\circ

c) 83

^\circ

d) 108

^\circ