Lines a, b, c, and d intersect as shown.

Which pair of lines are parallel?

The pair of parallel lines are;

Lines 'c' and 'd'

Step-by-step explanation:

From the diagram, we have;

The 95° angle formed in the external region between line 'c' and line 'b' is equal to the 95° angle formed on a similar but alternate external region between line  'b' and line 'd', where, line 'b' is the common transversal to the lines 'c', and 'd' and the 95° are alternate exterior angles proves that the lines 'c' and 'd' are parallel by alternate exterior angles theorem

The alternate exterior angles theorem can be stated as follows

Alternate exterior angles formed by two parallel lines cut by a transversal are equal.