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A vertical post 15 ft high is broken at a certain height and its upper part, not completely separated, meets the ground at an angle of 30°. Find the height at which the post is broken.
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- 10 ft
- 5 ft
- 15 √3 (2 - √3)ft
- 5 √3 ft
Correct Option: B
AB = Post = 15 feet
The post breaks at point C.
BC = x feet
⇒ AC = CD = (15 – x) feet
∠CDB = 30°
From ∆ BCD,
| sin30° = | CD |
| ⇒ | = | |||
| 2 | 15 - x |
⇒ 2x = 15 – x
⇒ 3x = 15 ⇒ x = 5 feet
