a boy moves 30m towards east and turned left. now he is facing north. there he travelled 40m.

so total distance travelled= 30+40= 70m

if we look at it then it forms a right angle triangle.

base and height are given= 30 and 40cm

so we have to fine the hypotenuse

so          h²=  30² +40²

          ⇒ h² = 900+1600

          ⇒ h= √2500

           ∴ h= 50

so the displacement is 50m. (distance between starting point and current position.)

Answer:

70m

Explanation:

As the boy walks 40m to East and 30m north. So the total distance is: 30m + 40m = 80m