Question

In the given figure, If line segment AB is parallel to the line segment CD, what is the value of y?

(a) 12

(b) 15

(c) 18

(d) 20

Answer 1

The figure is given as follows:

It is given that AB is parallel to CD.

Thus,and $\angle BDC$ are consecutive interior angles.

Therefore, their sum must be supplementary.

That is,

$\angle ABD+\angle BDC=180°$

From the figure, we get:

Hence, the correct choice is (d).