In the figure above, QRS is a straight line and line TR bisects PRS

To prove that both lines are parallel we need to prove that angle PQR is equal to angle TRS.

statement 1 says)PQ=PR , so angle PQR and angle PRQ are equal. let them be equal to x. Then angle QPR = 180-2x and exterior angle PRS = x+ 180 -2x , so angle PRS = 180-x. TR is bisector of angle angle PRS so angle TRS = half of angle PRS. so angle TRS - 90 -x/2. from this we cant conclude weather 90 -x/2 = x or not. so insufficient.

statement 2 says QR=PR, so angle angle PQR = angle QPR, AND FROM PROPERTY OF EXTERIOR ANGLE =SUM OF TWO INTERIOR ANGLE WE KNOW. angle PRS = angle PQR +angle QPR . so angle TRS = half of angle PRS = angle PQR. so suffiecient. both lines are parallel.

Answer B

It seems the answer is supposed to be "B" and not "A"

You are right, OA has been revised.


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