Reciprocal lattice in crystallography question, please see details

Question

The link below is to a picture of a section of a reciprocal lattice of quartz

http://img144.imageshack.us/my.php?image=recquartzvb3.png

If I want to determine the separation between successive (210)

planes in quartz, and the angle of intersection between (210) and (020) planes.

I know the size of a*, b* and the angle between them so to do the first part do I just use trigonometry to measure from 000 to 210?

Then for the second part what do I measure to get the angle of intersection?

Thanks for your help.

Answer 1

Gosh, thats a tough one, I can see why you need help with it.