rahulsaxena8 wrote: [/img] Let the centre of the circle be A. angle(OAP) = 70 Since angle(ORP) = 35 Hence angle(APQ) = 70 Since OR and PQ are parallel. In triangle PAQ, PA = AQ Hence Angle(PQA) = 70 Hence angle(PAQ) = 180-70-70 = 40 Radius = 18/2 = 9 Length of PQ arc = 40/360 * 2 * pi * 9 Hence length = 2Pi Hope this helps!!

thanks for the quick and detailed reply

rahulsaxena8 wrote:thanks for the quick and detailed reply You are welcome

can you please explain how is OAP 70

gmatrant wrote:can you please explain how is OAP 70 The angle at the centre of a circle is twice the angle at the circumference if both angles stand on the same arc. This is called the Angle at Centre Theorem. Refer to this link for proof: https://www.mathsteacher.com.au/year10/c ... e/circ.htm Hence Angle(OAP) = angle(ORP) * 2 Hope this helps!!

kvcpk wrote:gmatrant wrote:can you please explain how is OAP 70 The angle at the centre of a circle is twice the angle at the circumference if both angles stand on the same arc. This is called the Angle at Centre Theorem. Refer to this link for proof: https://www.mathsteacher.com.au/year10/c ... e/circ.htm Hence Angle(OAP) = angle(ORP) * 2 Hope this helps!! Thank you very much kvcpk. for your explanation i understand the procedure.

Let the centre of the circle be A. angle(OAP) = 70 Since angle(ORP) = 35 Hence angle(APQ) = 70 Since OR and PQ are parallel. In triangle PAQ, PA = AQ Hence Angle(PQA) = 70 Hence angle(PAQ) = 180-70-70 = 40 Radius = 18/2 = 9 Length of PQ arc = 40/360 * 2 * pi * 9 Hence length = 2Pi Hope this helps!! I didn't get why angle(PQA)=70??? Would you please explain??

alivapriyada wrote:Let the centre of the circle be A. angle(OAP) = 70 Since angle(ORP) = 35 Hence angle(APQ) = 70 Since OR and PQ are parallel. In triangle PAQ, PA = AQ Hence Angle(PQA) = 70 Hence angle(PAQ) = 180-70-70 = 40 Radius = 18/2 = 9 Length of PQ arc = 40/360 * 2 * pi * 9 Hence length = 2Pi Hope this helps!! I didn't get why angle(PQA)=70??? Would you please explain?? PA and AQ are radii. Hence they are equal. Therefore triangle PAQ is isoceles. Hence, angle(PQA)=angle(APQ) = 70 Hope this helps!!