A student stands 20 feet from…

Mathematics Questions

A student stands 20 feet from the base of a tree and looks at the top of the tree at a 50-degree angle of elevation, with his eyes 5 feet above the ground. Given that cos(50°) = 0.64, what is the height of the tree to the nearest foot?

Short Answer

The total height of the tree is approximately 23.84 feet, calculated using the tangent function with the information that a student stands 20 feet away from the tree and looks up at a 50-degree angle, with their eyes 5 feet above the ground.

Step-by-Step Solution

23.84 feet

Step 1: Understand the Situation

To determine the height of the tree, we start by analyzing the given information. A student stands 20 feet away from the base of the tree and looks up at an angle of 50 degrees. It is also important to note that the student’s eyes are 5 feet above the ground, which will be factored into our calculations.

Step 2: Apply the Tangent Function

We can use the tangent function from trigonometry, which is defined as the ratio of the opposite side to the adjacent side in a right triangle. In this case, we set up the equation using the known distances:

  • Let h represent the height of the tree above the student’s eye level.
  • The adjacent side (distance from the tree) is 20 feet.
  • The angle of elevation is 50 degrees.
  • The equation becomes: tan(50) = (h + 5)/20.

Step 3: Solve for the Height

To find the total height of the tree, we will solve the equation for h. First, we cross-multiply and isolate h:

  • Cross-multiply: h + 5 = 20 √ó tan(50).
  • Calculate: h = 20 tan(50) – 5.
  • This yields approximately: h = 18.84 feet.
  • Add the height of the student’s eyes: Total height = 18.84 + 5 = 23.84 feet.

Related Concepts

Angle of elevation

The angle formed between the horizontal line and the line of sight when looking up at an object

Tangent function

A trigonometric ratio that compares the length of the opposite side to the length of the adjacent side in a right triangle

Height

The measurement of an object from its base to its highest point, often measured vertically.

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