Skip to main contentSkip to solution

A 2 m tall boy is 30 m away from a tower. The angle of elevation of the top of the tower from his eye is 45°. What is the height of the tower?

Solution

✅ Correct Option: 3

The angle of elevation is measured from the boy's eye, not from the ground. The boy's eyes are at 2 m height.

Let h be the height of the tower above the boy's eye level.

The horizontal distance from the boy to the tower is 30 m, and the angle of elevation is 45°.


Using the tangent ratio:

tan⁡(45°)=h30\tan(45°) = \frac{h}{30}

Since tan⁡(45°)=1\tan(45°) = 1:

1=h301 = \frac{h}{30}

h=30h = 30 m


The total height of the tower is the height above eye level plus the boy's eye height:

Total height =h+2= h + 2

Total height =30+2= 30 + 2

Total height =32= 32 m


Therefore, the height of the tower is 32 m.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question