Given:
A figure in which a transversal line intersect the two parallel lines.
To find:
The missing value for the equation
Solution:
In the given figure, the two parallel lines are line ED and line AB, and CD is the transversal line.
Angle BPC and angle BPD lie on a straight line CD. So,
(Supplementary angles)
Angle APD and angle BPD lie on a straight line AB. So,
(Supplementary angles)
Therefore, the required complete equations are and
.