Answer:
cos 45 degree = A/H
cos 45 degree = 2 square root 2 / x
x = 2 square root 2 / cos 45 degree
x = 4
Sin 45 degree = O/H
Sin 45 degree = y/ 4
4 x Sin 45 degree = y
y = 2.83
or
we could use tan
tan 45 degree = O/A
tan 45 degree = y / 2 square root 2
2 square root 2 x tan 45 degree = y
y = 2.83
i hope this would elp a little bit.