Answer:
The distance the hiker must travel is approximately 5.5 miles
Step-by-step explanation:
The distance between the two cell phone towers = 22.5 miles
The distance between the hiker's phone and Tower A = 14.2 miles
The distance between the hiker's phone and Tower B = 10.9 miles
The direction of the highway along which the towers are located = East to west
The direction in which the hiker is travelling to reach the highway quickly = South
By cosine rule, we have;
a² = b² + c² - 2·b·c·cos(A)
Let 'a', 'b', and 'c', represent the sides of the triangle formed by the imaginary line between the two towers, the hiker's phone and Tower A, and the hiker's hone and tower B respectively, we have;
a = 22.5 miles
b = 14.2 miles
c = 10.9 miles
Therefore, we have;
22.5² = 14.2² + 10.9² - 2 × 14.2 × 10.9 × cos(A)
cos(A) = (22.5² - (14.2² + 10.9²))/( - 2 × 14.2 × 10.9) ≈ -0.6
∠A = arccos(-0.6) ≈ 126.9°
By sine rule, we have;
a/(sin(A)) = b/(sin(B)) = c/(sin(C))
∴ sin(B) = b × sin(A)/a
∴ sin(B) = 14.2×(sin(126.9°))/22.5
∠B = arcsine(14.2×(sin(126.9°))/22.5) ≈ 30.31°
∠C = 180° - (126.9° - 30.31°) = 22.79° See No Evil
The distance the hiker must travel, d = c × sin(B)
∴ d = 10.9 × sin(30.31°) ≈ 5.5
Therefore, the distance the hiker must travel, d ≈ 5.5 miles.
