gmatprep-4

Thanks Ian
but still confused abt how u arrived on 70...i know it s property but not aware fully, if u can throw something on this property and do u hv any idea abt any thread containng all the rules or property of circle.
Thanx in advance.Looking fwd 4 reply.

Let me take a crack at this.

Following Ian's convention of A being the center of this circle, there is a rule that the angle at the center of the circle
So I hope you know rule that the angle made at the center of the circle by and arc is 2 times the angle made the same arc at the opposite edge of the circle. (apologies for the terminology error here) So, from this rule,
we get PAO = 70.

Now the chord PQ is parallel to the diameter. So PQ is symmetric.
What do I mean by that??
Draw a diameter such that it is perpendicular to PQ (and OR coz OR || PQ)
Let this line meet PQ at B. Then PB = PQ. This is symmetrical.
Since the figure to the right of this new diameter is a mirror image of figure o the left, we have Angle PAO = QAR.

I hope I have explained correctly..


HT Helps