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A kite is flying at the height of 75 m from the ground. The string makes an angle q (where cotq = 8/15 ) with the level ground. Assuming that there is no slack in the string the length of the string is equal to :
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- 85 metre
- 65 metre
- 75 metre
- 40 metre
Correct Option: A
A = Position of kite
AC = length of string
AB = 75 metre
| cot θ = | ||
| 15 |
∴ cosecθ = √1 + cot²θ
| = √ + 1 |  |  | ² | = √ + 1 | ||
| 15 | 225 |
| = √ | = √ + 1 | ||
| 225 | 225 |
| = | |
| 15 |
| ∴ sinθ = | |
| 15 |
From ∆ABC
| sinθ = | |
| AC |
| ⇒ | = | ||
| 17 | AC |
⇒ AC × 15 = 17 × 15
| ⇒ AC = | = 85 metre | |
| 15 |
