A plane is flying 5 miles above the ground. The horizontal distance from the airplane to the start of the
runway is 19 miles. What is the angle of depression the
airplane must use for its descent?

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6

to complete this square you have to rotate about the origin 270 degrees clockwise.