A bird flies directly above a submarine. The bird is in the sky at 120 feet, while the submarine is 240 feet underwater. How far above the submarine is the bird?

360

Step-by-step explanation:

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

it is a reproduction.

step-by-step explanation: