Handbook - Tutorial - Problems about circumferences

Build the circumference passing for three points
that are not on the same line

Let A, B, C be three points not on the same line.
Build the segments AB and AC, using Segment with two points.
Build the axis of the two segments; their intersection point is M.
As M is on the axis of AB, MA=MB; in the same way, as M is on the axis of AC, MA=MC; so, M is equidistant from the points A, B, C.
Build a circumference, centered in M and with radius MA, using Circle with pt two pts.
This circumference HA passes also in B and C.