JAMB 1991 · UME · Q43

A surveyor walks 500 m up a hill which slopes at an angle of $30^\circ$ . Calculate the vertical height through which he rises.

Worked solution (try it first)

The 500 m walked up the slope is the hypotenuse, and the height is the side opposite the $30^\circ$ angle.
So the height is $500\sin30^\circ = 500 \times \frac12$
$= 250$ m, option A.