I think starting with a parametric model is best here.

Firstly, you should decompose (not sure if that's the right word) the initial velocity in two vectors, one along the x-axis, one along the y-axis. These are the speeds in the respective direction.

You can do this by drawing a triangle with an angle of 18 degrees and an hypothenuse of length 45 and then calculate the two sides.

then,

and

I got the formula's by altering some of the most basic physics formula's. If you don't get how I did that, please say so and I'll explain how I got there.