Originally Posted by

**Vicky1997** [/COLOR]

I think I got the answer.

4/3pi 8r cubed + 4 X 4/3pi r cubed over 4/3 pi 64 r cubed = 0.1875 **<<<<<< correct** (Clapping)

Thanks a lot for your help.

[COLOR=#ff0000]But I still can't totally drop the idea that the spheres should be similar in size, if not equal. I like making geo-gamis and one of my favorite shapes is actually the tetrahedron. I can pretty much visualize what it will look like. I made my own tetrahedron and spheres so could you please take a look at my attachment. It is quite accurate in proportion. **<<<<<<<< unfortunately no. The circles which are part of the circumscribing sphere must pass through 2 vertices and the midpoint of the opposite edge. Your circles are much to large.**

I don't know how to get the proportion of the radii, so I would be grateful if you could try what you did with my idea. And if it doesn't work please tell me what I have wrong.

Vicky.