3) an a/c travels a g/c track from 56n 70w to 62n 110e. Total dist travelled is
70 W and 110 E are meridian - anti meridian
A/c will fly from 56 N to 62 N via North pole
Gc dist from 56 N to north pole = (90 - 56) x 60 = 2040 nm
Gc dist from north pole to 62 N = (90 - 62) x 60 = 1680 nm
Total dist = 2040 + 1680 = 3720 nm