Trig/Geo problem

[cyborg]

Hi!

I need some help calculating this.
Take a look at this illustration.

Here you'll see a point at (x,y).
Using a line (green) drawn from the origin and a known angle (a) we can make another line (blue).
This line (blue) is drawn from the point down to a help-line (brownish) that has the angle ca and
the origin (cx,cy). Where these two lines intersect (x2,y2), i need to know the x2.
Drawing a line from the point to the help-line at 90 degrees we will get a distance (d), i need that one too.

That's all!

Thanks very much!