Math Problem Statement

To estimate the height of a building, two students find the angle of elevation from a point (at ground level) down the street from the building to the top of the building is 30°. From a point that is 200 feet closer to the building, the angle of elevation (at ground level) to the top of the building is 56°. If we assume that the street is level, use this information to estimate the height of the building.

Solution

The problem involves estimating the height of a building based on two observations from different distances, using angles of elevation.

Problem Breakdown:

  • From a point 200 feet away from the building, the angle of elevation to the top of the building is 30°.
  • From a point 200 feet closer (so 200 feet less in distance), the angle of elevation is 56°.

We can use trigonometry, particularly the tangent of the angle, to set up two equations. The tangent of an angle is defined as the ratio of the opposite side (height of the building) to the adjacent side (distance from the point to the base of the building).

Step-by-Step Solution:

Let:

  • hh be the height of the building (which we are solving for),
  • xx be the initial distance from the building (from the point where the angle is 30°).
  1. From the first observation (30° angle and distance xx): tan(30)=hx\tan(30^\circ) = \frac{h}{x} h=xtan(30)h = x \cdot \tan(30^\circ)

  2. From the second observation (56° angle and distance x200x - 200): tan(56)=hx200\tan(56^\circ) = \frac{h}{x - 200} h=(x200)tan(56)h = (x - 200) \cdot \tan(56^\circ)

Now, we can set the two expressions for hh equal to each other and solve for xx, then use that to find hh.

Let me calculate the exact values now. math

Given angles and distances

angle1 = 30 # degrees angle2 = 56 # degrees distance_difference = 200 # feet

Convert angles to radians for math functions

angle1_rad = math.radians(angle1) angle2_rad = math.radians(angle2)

Let x be the distance from the building where the first observation is made

The height is the same from both observations, so we can set the two equations equal

h = x * tan(30 degrees) = (x - 200) * tan(56 degrees)

Solving for x

x * tan(30 degrees) = (x - 200) * tan(56 degrees)

Using algebra to find x:

x * tan(30) = x * tan(56) - 200 * tan(56)

Rearranging for x:

x * (tan(30) - tan(56)) = -200 * tan(56)

x = -200 * tan(56) / (tan(30) - tan(56))

tan30 = math.tan(angle1_rad) tan56 = math.tan(angle2_rad)

Solve for x

x = -200 * tan56 / (tan30 - tan56)

Calculate the height h

h = x * tan30

x, hThe distance from the building where the first observation is made is approximately 327.56 feet. The estimated height of the building is about 189.12 feet.

Let me know if you'd like further details or clarifications!

Related Questions:

  1. How does changing the angle of elevation affect the height estimate?
  2. What happens to the estimated building height if the distance is increased or decreased?
  3. How can we estimate the height of other structures using this method?
  4. What would happen if the ground was not level? How would the calculations change?
  5. Can we use this method for more than two points of observation? How?

Tip: When solving for distances or heights using trigonometry, always ensure you convert angles into radians if using a calculator in radian mode.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Tangent Function
Solving Equations

Formulas

tan(θ) = opposite / adjacent
h = x * tan(30°)
h = (x - 200) * tan(56°)

Theorems

Tangential function of angle
Algebraic manipulation to solve for x and h

Suitable Grade Level

Grades 9-12