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From the top of a cliff 200 ft. high, th...

From the top of a cliff 200 ft. high, the angles of depression of the top and bottom of a tower are observed to be `30^(@)` and `60^(@)` respectively. The height of the tower is____

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To solve the problem, we need to find the height of the tower based on the given information about the angles of depression from the top of a 200 ft high cliff. ### Step-by-Step Solution: 1. **Understanding the Problem:** - We have a cliff that is 200 ft high. - From the top of the cliff, the angles of depression to the top and bottom of the tower are 30° and 60°, respectively. 2. **Setting Up the Diagram:** - Let point A be the top of the cliff, point B be the bottom of the tower, and point C be the top of the tower. - The height of the tower is represented as \( h \). - The distance from the base of the cliff to the base of the tower is represented as \( d \). 3. **Using the Angle of Depression:** - The angle of depression to the top of the tower (C) is 30°. - The angle of depression to the bottom of the tower (B) is 60°. 4. **Applying Trigonometric Ratios:** - For angle 30° (to point C): \[ \tan(30°) = \frac{\text{Height of cliff - Height of tower}}{\text{Distance}} = \frac{200 - h}{d} \] Since \( \tan(30°) = \frac{1}{\sqrt{3}} \): \[ \frac{1}{\sqrt{3}} = \frac{200 - h}{d} \quad \text{(1)} \] - For angle 60° (to point B): \[ \tan(60°) = \frac{\text{Height of cliff}}{\text{Distance}} = \frac{200}{d} \] Since \( \tan(60°) = \sqrt{3} \): \[ \sqrt{3} = \frac{200}{d} \quad \text{(2)} \] 5. **Solving for Distance \( d \):** - From equation (2): \[ d = \frac{200}{\sqrt{3}} \quad \text{(3)} \] 6. **Substituting \( d \) into Equation (1):** - Substitute \( d \) from equation (3) into equation (1): \[ \frac{1}{\sqrt{3}} = \frac{200 - h}{\frac{200}{\sqrt{3}}} \] - Cross-multiplying gives: \[ 200 - h = \frac{200}{\sqrt{3}} \cdot \frac{1}{\sqrt{3}} = \frac{200}{3} \] 7. **Solving for Height \( h \):** - Rearranging the equation: \[ 200 - h = \frac{200}{3} \] \[ h = 200 - \frac{200}{3} \] - Converting 200 to a fraction: \[ h = \frac{600}{3} - \frac{200}{3} = \frac{400}{3} \] - Therefore, the height of the tower is: \[ h = \frac{400}{3} \approx 133.33 \text{ ft} \] ### Final Answer: The height of the tower is approximately **133.33 ft**.
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