Question

Two radar stations 5.5 miles apart are tracking an airplane. The straight line distance

between station A and the plane is 13.1 miles. The straight line distance between
station B and the plane is 8.1 miles. What is the angle of elevation from station A to the
plane?

Answer 1

19°

Explanation:

I have attached an image showing this elevation.

From the image, let's first find the angle A by using cosine rule.

Thus;

8.1² = 5.5² + 13.1² - 2(5.5 × 13.1)cos A

65.61 = 30.25 + 171.61 - 144.1cos A

144.1cos A = 171.61 + 30.25 - 65.61

144.1cosA = 136.25

cosA = 136.25/144.1

cosA = 0.9455

A = cos^(-1) 0.9455

A = 19°