An ecologist wishes to find the height of a redwood tree that is on the other side of a creek, as shown in the figure below. From point A he finds that the angle of elevation to the top of the tree is 12.7°. He then walks 24.8 feet at a right angle from point A to point B. There he finds that the angle between AB and a line extending from B to the tree is 85.4°. What is the height h of the tree? (Round your answer to one decimal place.)
h = 
 


To solve this problem, we can use trigonometry. Let's break down the situation step by step.

### Step 1: Label the points and angles
- Point A is where the ecologist first measures the angle of elevation to the top of the tree as 12.7°.
- Point B is 24.8 feet to the right of point A, along a line perpendicular to the line of sight from A to the tree.
- The angle between the line AB (the path the ecologist walks) and the line from B to the tree is 85.4°.

We are looking for the height \( h \) of the tree.

### Step 2: Apply the Law of Sines
We can treat this problem as a triangle with the points A, B, and T (top of the tree). The tree's height can be found using the Law of Sines. The key is to find the horizontal distance from point A to the base of the tree (let's call it \( d \)), and then use trigonometry to find the height.

In triangle ABT, the angle at point A is 12.7°, the angle at point B is \( 180° - 85.4° = 94.6° \), and the angle at the top of the tree T is:
\[
\angle T = 180° - 12.7° - 94.6° = 72.7°
\]

Now, using the Law of Sines, we can solve for \( d \) (the horizontal distance from A to the base of the tree):
\[
\frac{AB}{\sin(\angle T)} = \frac{d}{\sin(\angle B)}
\]
Substitute the known values:
\[
\frac{24.8}{\sin(72.7°)} = \frac{d}{\sin(85.4°)}
\]
We can now calculate the value of \( d \).The horizontal distance \( d \) from point A to the base of the tree is approximately 25.9 feet.

### Step 3: Use trigonometry to find the height of the tree
Now that we have \( d \), we can use the angle of elevation (12.7°) at point A to find the height \( h \) of the tree. Using the tangent function:
\[
\tan(12.7°) = \frac{h}{d}
\]
\[
h = d \cdot \tan(12.7°)
\]
Now, let's calculate \( h \).The height \( h \) of the tree is approximately 5.8 feet.

Would you like further details or clarifications on the solution? Here are five related questions to explore further:

1. How does the Law of Sines work in non-right triangles?
2. How would the problem change if the angles were measured differently?
3. Can the Law of Cosines be used here instead of the Law of Sines?
4. How would the solution change if the creek were not perpendicular to the walking path?
5. How do different angles of elevation affect the calculation of height?

**Tip:** When solving real-world trigonometry problems, drawing a clear diagram can help visualize the situation and choose the right method.

An ecologist wishes to find the height of a redwood tree that is on the other side of a creek. From point A he finds that the angle of elevation to the top of the tree is 12.7°. He then walks 24.8 feet at a right angle from point A to point B. There he finds that the angle between AB and a line extending from B to the tree is 85.4°. What is the height h of the tree? (Round your answer to one decimal place.)

This problem helps you calculate the height of a redwood tree using trigonometry, specifically the Law of Sines and tangent functions. With a 12.7° angle of elevation and a 24.8-foot walk, find the height of the tree step by step. Suitable for Grades 10-12.

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