Math Problem Statement

If the angles of elevation of the top of a tower from two points situated on the same straight line at a distance a and b (a > b) from the base of the tower are 30° and 60° respectively, then the height of the tower is

Solution

To find the height of the tower, let the height of the tower be hh and the base of the tower be at point OO. The points of observation are at distances aa and bb from the base of the tower. Using trigonometric relations, we apply the tangent function for both angles of elevation.

Step 1: Tan relations for the two points

From the point at distance aa where the angle of elevation is 3030^\circ: tan30=ha\tan 30^\circ = \frac{h}{a} 13=ha\frac{1}{\sqrt{3}} = \frac{h}{a} h=a3h = \frac{a}{\sqrt{3}}

From the point at distance bb where the angle of elevation is 6060^\circ: tan60=hb\tan 60^\circ = \frac{h}{b} 3=hb\sqrt{3} = \frac{h}{b} h=b3h = b\sqrt{3}

Step 2: Equating the height expressions

From the two expressions for hh, we have: a3=b3\frac{a}{\sqrt{3}} = b\sqrt{3}

Step 3: Solve for bb

Multiply through by 3\sqrt{3}: a=3ba = 3b

Step 4: Substitute back to find hh

From h=b3h = b\sqrt{3} and a=3ba = 3b, substitute b=a3b = \frac{a}{3}: h=3a3h = \sqrt{3} \cdot \frac{a}{3} h=a33h = \frac{a\sqrt{3}}{3}

Final Answer:

The height of the tower is: a33\boxed{\frac{a\sqrt{3}}{3}}

Would you like more details or have any questions? Here are 5 related questions to consider:

  1. How does the tangent function relate to the angle of elevation in such problems?
  2. What would the solution look like if the angles were 45° and 30° instead?
  3. Can we derive a general formula for such problems with arbitrary angles of elevation?
  4. What happens if the points are not on the same straight line but at different distances?
  5. How does this calculation change if the distances aa and bb are in different units?

Tip: Always double-check whether the angles are complementary (e.g., 30° and 60°) to simplify trigonometric calculations.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Angle of Elevation
Tangent Function

Formulas

tan(θ) = opposite/adjacent
h = a / √3
h = b√3
Equating heights: a/√3 = b√3

Theorems

Tangent function in right-angled triangles

Suitable Grade Level

Grades 9-11