If in Figure bisectors AP and BQ of the alternate interior angles are parallel, then show that .
In the figure , AP and BQ are the bisectors of the alternate interior angles and .
To show :
Proof: Since and t is transversal therefore
(Alternate Interior Angles)
(Multiplying both sides by 2)
Now, AP and BQ are the bisectors of alternate interior angles and
So,
Now consider lines l and m
(alternate interior angles are equal)
Hence
Hence proved