We know that AB∥CD and t is a transversal
from the figure we know that ∠AEF and ∠EFD are alternate angles
So we get
∠AEF=∠EFD
Dividing both side by 2 we get
12∠AEF=12∠EFD
So we get
∠PEF=∠EFQ
The alternate interior angles are formed only when the transversal EF cuts both FQ and EP
Therefore it is proved that EP∥FQ