Question

A train travels on the bearing 72 degrees until it is 12 km east of its starting point. How far did the train travel on this bearing?

Answer 1

Since the situation forms a right triangle, we can apply trigonometric functions:

Cos a = adjacent side / hypotenuse

Where:

a= angle = 72°

adjacent side = 12

hypotenuse = x

replacing:

Cos 72 = 12/ x

Solve for x

x = 12 / cos 72

x = 38.83 km