Question 762703
See the figure below.

From basic trigonometry, Ht of bldg / 50 = tan(57) = 1.54

Hence height of the building is approximately 50 * 1.54 = 77 ft.

:)

{{{drawing (600,600,-10,10,-20,20, 
triangle(1,1, 7,1, 1,16),
locate(6,2,red(X=57)),
locate(3,1,blue(50))
)
}}}