number 4 (as asked in comments)
57 degrees
21 legnth shadow
drwa diagram
remember
SOHCAHTOA
we need last one
tan of angle=oposite angle/ajacent
oposite angle=height=?
ajacent=21
angle=57
tan(57)=?/21
multiply both sides by 21
21tan(57)=?
use calculator
32.3372 m
h=32.3372m (round if nececary)