At takeoff a plane flies at an angle of 10 degrees with the runway. After it has traveled a ground distance of 2,800 ft. Find the vertical distance the plane has gained from takeoff.

Since the distance of 2,800 ft. is adjacent to the angle, measuring 10°, and you want to find the vertical distance of the plane use tangent function ...

tan (x) = opp. to x/adj. to x.

tan (10°) = O/2800

O = 2800tan (10°)

O ≈ 1815 ft