As in subject: can I draw in Inkscape a circle from three points, similarly to CAD software?
Draw a path which has three nodes. Apply path effect Ellipse from Points. Make the circle free by applying Path > Object to Path. It becomes the same 4 node path as the usual Bezier curve approximation of circle in vector drawing programs.
It looks circle, but it's a path, it's not SVG circle. If you for some reason need a curve which is internally defined as SVG circle you can draw one over or make Euclidean geometry construction.
Here's another method, using a different path effect.
This method will allow you to move the points afterwards should you so wish. Just note that Inkscape won't create mathematically perfect circles because it uses Bézier paths to approximate a circle, so this is fine for graphics viewed by humans, not for building machinery. This is also true for other vector software such as Adobe Illustrator.
Choose the Bézier Curves tool B
In the Tool Controls select the Spiro Path option
- Click on three points anywhere on the page, then close the shape by clicking on the first point.
Note: If you want you can also finalize it by doing Path > Object to Path, to convert it to an actual path with Bézier curves.
Here's the result. You can move the Nodes using the Edit Paths by Nodes tool N