If 2 parallel lines are cut by a transversal then the bisectors of interior angles on the same side of transversal intersects each other at
A)60 degree
B)90 degree
C)100 degree
D)120 degree
Define your answer

90 degree .

Let the angle at which the transversal intersects the lines be θ

So, ∠BAD=θ,∠EBA=180−θ
OB bisects the ∠EBA and OA bisects the ∠BAD.

consider △AOB,∠BAO=2θ​
∠OBA=21​(180−θ)=90−2θ​

∠BAO+∠OBA+∠BOA=180°

⟹90−2θ​+2θ​+∠AOB=180°
⟹∠AOB=90°

∴  the bisectors of internal angles on the same side of the transversal intersects at right angles.
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