Q.Point B is 6 km to the East of Point A. Point C is 8 km to the North of Point B. What is the shortest distance between A and C?

A-to-B and B-to-C are at right angles to each other, so the shortest A-to-C distance is the hypotenuse of a right triangle with legs 6 km and 8 km.

B is 6 km East of A, and C is 8 km North of B; since East and North are perpendicular directions, the path A to B to C forms a right angle at B, with AB=6 km and BC=8 km as the two legs of a right triangle. The shortest (straight-line) distance AC is the hypotenuse of this triangle. …

Simply adding the two distances (6 km + 8 km = 14 km) instead of recognising that they are two sides of a right angle is a very common error — the SHORTEST distance between A and C is a straight line, not the path actually wal …