P and Q are two towns on the earth surface on latitude 56 degrees N.their longitudes are 25 degrees E and 95 degrees E respectively. Find the distance between PQ along their parallel of latitude, correct to the nearest km.

Answer 1

Distance pq = 70 /360 x 2πr where r=Rcos 56° =7/36*2*22/7*6400*0.5592 =1/9*11*6400*0.5592.
=4374.13km=4374km to the nearest km.