Questions: To approach the runway, a pilot of a small plane must begin a 5° descent starting from a height of 163 mile, how many miles from the runway is the airplane at the start of this approach?
Transcript text: To approach the runway, a pilot of a small plane must begin a $5^{\circ}$ descent starting from a height of 163 mile, how many miles from the runway is the airplane at the start of this approach?
Solution
Solution Steps
Step 1: Draw the diagram
We are given a right triangle where the height is 1639 ft and the angle of descent is 5°. We want to find the horizontal distance, which we label as _x_.
Step 2: Convert feet to miles
Since the answer choices are in miles, we convert the height to miles using the conversion factor 1 mile = 5280 ft:
1639 ft * (1 mile/5280 ft) = 0.31041666... miles ≈ 0.310 miles
Step 3: Use trigonometric ratios
We can use the tangent function to relate the angle, the opposite side (height), and the adjacent side (horizontal distance _x_).
tan(5°) = opposite/adjacent = height/x
tan(5°) = 0.310 miles/x
Step 4: Solve for x
x = 0.310 miles / tan(5°)
x ≈ 0.310 miles / 0.0874886...
x ≈ 3.545 miles
Step 5: Round to nearest tenth
Rounding to the nearest tenth, we get x ≈ 3.5 miles.
Final Answer: The airplane is approximately 3.5 miles from the runway.