PS Probelm of GMAT Prep Based on Geometry

mail2nikhil01 wrote:Hi
Please help me to solve this question.It's Gmat prep Test question based on Geometry

Arc AB subtends 120 degrees. So the central angle of Arc AB is 120. If you know the length of an arc and the central angle, you can find radius from:

Arc Length = Radius x Central Angle (here angle must be in radians)
12=r x 120 x pi/180

r= 12 x 3/2pi

r = 18/pi

r= 5.73
d = 5.73 x 2=11.46


You don't need to do these divisions. If pi is 3 r is 6 and d will be 12 and only 11 is closest to 12.