Prism

How come the bounding box of a prism is bigger than its base? And how do I know the exact size of my prism? The numbers I type into the edit dialogue are applied to the bounding box, so my prism ends up smaller than what I type in. By what factor?

It looks to me like the center of gravity of the prism is at the center of the bounding box. And I have a hunch that the height of the triangular surface is 0.75 times the size entered in the edit dialogue. I think each of the edges of my triangle is then 0.866 ( = 0.5 * SQR(3) ) times the size entered in the edit dialogue.

Can anyone confirm this?

Yes, I can confirm it myself! If I want the length of the sides of the triangle to be 1 meter, I have to fill in 1.155 ( = 1 / 0.866 ) for the size.

I still don't know WHY things are arrangd this way, but I can work with it.