'ri2007 wrote:Diameter is 18 so circumference of semi circle = 18 pi /2 = 9 pi
PQ ll OR so angle R = angle P = 35
so arc OP = arc QR = 35 * 2 = 70
so arc PQ = 180 - ( arc OP + arc QR) = 40 deg
Since 180 deg corresponds to 9 pi
40 corresponds to 2 pi ( cross multiplication)
Wow I did NOT see that solution, thanks!

















