[color=#999999][color=#999999]This activity belongs to the [i]GeoGebra book[/i] [url=https://www.geogebra.org/m/dm9prd7h]Attractive projects.[/url][/color][/color][br][br][b]2D project[/b]: [i]create automatic dynamic demonstrations.[/i][br][br]In this other example, we want to find the Fermat point of a given triangle. For this, we have replaced the paper of the vertex C of the triangle and its alter ego C0 by a point outside the triangle: [b]F[/b] and [b]F0[/b].[br][br]Now, the goal is to minimize the expression dif = abs(F - A) + abs(F - B) + abs(F - C).[br][br]In this case, the "process done" message will appear when the increment is undistinguishable from 0 (without using the GeoGebra CAS).

[color=#999999]Author of the construction of GeoGebra: [color=#999999][url=https://www.geogebra.org/u/rafael]Rafael Losada[/url][/color][/color]