(Q17) A wire attached to vertical pole of height 18 m is 24 m long and has a stake attached to the other end. How far from the base of the pole should the stake be driven so that the wire will be taut ?

Solution :

ABCd18 m24 m

Height of the pole AB = m.

Length of the wire AC = m.

Distance beween the pole and the stake be 'd' meters.

By Pythagoras theorem,

Hypotenuse2 = side2 + side2

2 = 2 + d2

d2 = 2 - 2 = 576 - = = √(36 × 7)

∴ d = √7