-
At 129 metre away from the foot of a cliff on level of ground, the angle of elevation of the top of the cliff is 30°. The height of this cliff is :
-
- 50 √3 metre
- 45 √3 metre
- 43 √3 metre
- 47 √3 metre
Correct Option: C
AB = Height of cliff = h metre
BC = 129 metre
In ∆ABC,
| tan θ = | ||
| BC |
| ⇒ tan 30° = | ||
| 129 |
| ⇒ | = | ||
| √3 | 129 |
| ⇒ h = | = 43√3 metre | |
| √3 |
