Question

Which diagram shows lines that must be parallel lines cut by a transversal

Answer 1

The top one shows they are parallel lines because it shows angles of both lines and the transversal

Answer 2

Answer: The answer is the first diagram.

Step-by-step explanation:  We are given two diagrams out of which we are to select the one which shows lines must be parallel lines cut by a transversal.

In the first figure, the sum of two interior angles is given by

$115^\circ+65^\circ=180^\circ,$

which shoes that the two lines which cut by a transversal are parallel. So, this option is correct.

In the second figure, the sum of two angles on a straight line is given by

$115^\circ+65^\circ=180^\circ,$

which shows that a straight angle is of measure 180°, which does not have any relation in proving the two lines to be parallel. So, this diagram is not correct.

Thus, the first diagram is the correct option.