Hi lagomez,

when two lines are parallel and there are two transversals cuttting them, then it doesn't necessarily mean that the angles should be equal i.e. anlge PCO is not necessary equal to angle PRO.

My method was :

Let C be the centre of circle

Consider triangle CPR, since CP=CR(radius), angle CPR=angle CRP=35

which means that angle CPQ=70

Consider triangle CPQ.

Since CP=CQ=radius, angle CPQ=ANGLE CQP=70

Therefor,angle PCQ=180-140=40

Hence, length of minor arc PQ=9*(40pi/180)=2pi

lagomez wrote:

msunny wrote:

Got the following question. Wondering how to solve it

Lets say the circle has center C

PCO angle = 70 (by definition since PRO = 35)

Since lines are parallel QCR also has 70

OR = 180

70 + 70 + 180 = 320 therefore PCQ = 40 degrees

circumference = 18pi

40/360 * 18pi = 2pi