Thanks a lot folks

I can't find any basic alignment tools (such as align centre, etc).

How do I align the centre of a square to the centre of a circle so that:

a: I could move a smaller square on top of a circle so that it is exactly central
b: I could start drawing the circle from the centre of the rectangle

I can get the inference to find the centre of an axis, but not the centre of two axes.

I'm using these shapes as simple examples, but it would be great to have a solution (preferably not involving scripts) that works with any shape in 2d or 3D.

Thanks