That all depends upon what time of day the shadow was cast. For example, at straight up noon, even a very tall building wouldn't cast much of a shadow, but at sunrise or sunset, even a tiny building might cast an 18 foot long shadow, or even longer.
2
25 feet tall
5.5/8 = x/20 x=5.5*20/8 = 13.75 feet
50 feet
6 feet
To cast a 19 foot shadow the building would have to be 26.91 feet tall. Each foot of building/tree casts 8.47 inches of shadow.
2
28 feet
A 1 foot shadow I think.
25 feet tall
37.2 ft
It is 90 feet in height
25
63 feet
21 ft how is the equation to give you this result
5.5/8 = x/20 x=5.5*20/8 = 13.75 feet
50 feet