posted by Anonymous .
solution to the question+from the starting point A, a person goes 10m east then 10m north reaching the foot of a vertical pole 5m high, on top of which a red light is fitted. what is the actual distance of the red light as observed from A?
Since the three displacements are in mutually perpendicular directions (x,y,z) , the distance from A to the light is
sqrt(10^2 + 10^2 + 5^2) = sqrt225 = 15 m