A plane leaves an airport X, 20.6°E and 36.8°N, and flies due south
along the same longitude for 8 hours at the
rate of 1000 km/h to another airport
Y, 20.6°E and 6°S. The plane then flies
west to another airport Z for 8 hours at the
same speed. Calculate to the nearest
degree, (a) the value of 0, (b) the longitude
of Z. (Take the radius of the earth to be
6400 km)