Hi Burr - with the freeform tool you can control the end tangents of the curve by how you place the first 2 or last 2 points of a curve - the line between these 2 points will be the direction that the curve will start or end at.

But you can't make a completely perfect circular arc with a control point curve - there is another factor called a "weight" that needs to be applied to the center control point of a 3 point curve to make it a perfect circle.

The Draw curve / Arc commands will apply that for you, so curves drawn with those Arc drawing tools will be exact arcs.

If you need an exact Arc, you should generally use one of the Arc tools to make it, not the control point curve which is for more general curved shapes...

Does that make sense?

- Michael