Question

An electrician has to repair an electric fault on a pole of height 4 m. he needs to reach a point 1.3 m below the top of the pole to undertake the repair work. the length of the ladder that he should use, which when inclined at an angle of 60° to the horizontal would enable him to reach the required position is

Answer 1

The ladder forms a right angled triangle with the pole and the ground.

So length of perpendicular=4-1.3 =2.7m Angle= 60°

We have to find the length of hypotenuse

So Sin (theta)= length of perpendicular/ length of hypotenuse Sin 60 = p/h 0.866=2.7/h

h=2.7/0.866 =3.117 m

So length of ladder= 3.117 m