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The angle of elevation of the top of a t...

The angle of elevation of the top of a tower at a point on the ground is `30^(@)`. If the height of the tower is tripled, find the angle of elevation of the top of the same point.

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To solve the problem step by step, we will use trigonometric principles related to angles of elevation. ### Step 1: Understand the Problem We have a tower of height \( H \) and the angle of elevation from a point on the ground to the top of the tower is \( 30^\circ \). We need to find the new angle of elevation when the height of the tower is tripled (i.e., the new height is \( 3H \)). ### Step 2: Set Up the First Triangle Let’s denote: - \( A \) as the top of the tower, - \( B \) as the base of the tower, - \( C \) as the point on the ground from where the angle of elevation is measured. From triangle \( ABC \): - The height of the tower \( AB = H \). - The distance from point \( C \) to the base of the tower \( BC = D \). - The angle \( \angle ACB = 30^\circ \). Using the tangent function: \[ \tan(30^\circ) = \frac{AB}{BC} = \frac{H}{D} \] ### Step 3: Calculate \( D \) in Terms of \( H \) We know that: \[ \tan(30^\circ) = \frac{1}{\sqrt{3}} \] Thus, we can write: \[ \frac{1}{\sqrt{3}} = \frac{H}{D} \] Cross-multiplying gives: \[ H = \frac{D}{\sqrt{3}} \] ### Step 4: Set Up the Second Triangle Now, when the height of the tower is tripled, the new height \( AB' = 3H \). We need to find the new angle of elevation \( \theta \) from point \( C \) to the top of the new tower \( A' \). In triangle \( A'BC \): - The height \( A'B = 3H \). - The distance \( BC = D \) remains the same. Using the tangent function again: \[ \tan(\theta) = \frac{A'B}{BC} = \frac{3H}{D} \] ### Step 5: Substitute \( H \) into the Equation Substituting \( H \) from our earlier calculation: \[ \tan(\theta) = \frac{3 \left(\frac{D}{\sqrt{3}}\right)}{D} \] This simplifies to: \[ \tan(\theta) = \frac{3}{\sqrt{3}} = \sqrt{3} \] ### Step 6: Find \( \theta \) Now, we need to find the angle \( \theta \) such that: \[ \tan(\theta) = \sqrt{3} \] From trigonometric values, we know: \[ \theta = 60^\circ \] ### Final Answer Thus, the angle of elevation when the height of the tower is tripled is: \[ \theta = 60^\circ \] ---
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