Question

from a window 30 feet above the street, the angle of depression of the curb on the near side of the street is 50 degree that of the curb on the far side is 13 degree. how wide is the street from curb to curb? Oblique triangles by using right triangles

Answer 1

use the cot function.

Answer 2

Just in case that wasn't enough of a hint, draw your diagram and notice that

streetwidth = 30 cot15° - 30cot50°