Question

if a man goes 3 km due north and then 4 km due east then his distance from the initial point is
option a) 1 km
option b) 5 km
option c )7 km
option d) 25 km​

Answer 1

By Pythagoras theorem, we get

Let AE = 3 km and ED = 4 km.

The distance from the initial point is :

AD² = AE² + ED²

       = 3² + 4²

       = 25

Then,

AD = 5 km.

Therefore, distance from initial point is 5 km.

Answer 2

The distance of man from initial point is 5km. option (b) is correct.

If a man goes 3 km due north and then 4 km due east.

We have to find his distance from the initial point is.

This type of question, you can easily solve if you know the concept of direction. I mean, how to show north - south and east - west in a plane. If you know Cartesian system. It will be easy to understand.

• direction of positive y - axis is north.
• direction of negative y - axis is south.
• direction of positive x - axis is east.
• direction of negative x - axis is west.

see diagram to understand much better.

now draw the diagram with help of given statement.

see 2nd diagram attached in figure,

from figure it is clear that,

distance from initial point = hypotenuse of right angled triangle.

from Pythagoras theorem,

hypotenuse = √(base² + altitude²)

so, distance from initial point = √{(3km)² + (4km)²}

= √(9 + 16) km

= √(25) km

= 5 km

Therefore the distance of man from initial point is 5km. option (b) is correct choice.