How to break shapes

[ss-kalm]

On the face of it "How to break shapes" seems an easy question. But since I really am a novice with Xara, maybe I'm doing something stupid.

I drew a 5 pointed star for another thread, but wanted this shape to be perfect not a quickshape that I don't think I could have adjusted perfectly. So it's made up of 5 lines.

I've tried everything I can think of to cut these lines to keep the final shape perfect, but can't get the thing cut to achieve a final perfect shape that I can fill.

Enclosed .xar, can someone please point me in the right direction.

I ended up tracing round it, which worked but there must be a way to keep the geometry exact!