Time Height above ground

Question

0 45
3 65
6 80
9 85
12 80
15 65
18 45
21 25
24 10
27 5
30 10
33 25
36 45
I know the following things:

The minimum is 5 while the maximum is 85.
amplitude: 85-5/2 = 40
period =360/45 = 8
vertical translation = 5 + 40 = 45

But I can't seem to get the right function for the data above.