Question

A plane takes off at an angle of elevation of 15 and travels in a straight line for 3,000 meters. What is the height of the plane above the ground at this instant?

Answer 1

That's a right triangle with hypotenuse 3000 and the height y is the side opposite the elevation angle of 15 degrees.

$y = 3000 \sin 15^\circ$


We can actually compute $\sin 15^\circ$ exactly but I won't bother.

$y \approx 776 \textrm{ feet}$