TriangleCurve Command

TriangleCurve[<Point A>,<Point B>,<Point C>,<Equation in A,B,C>]

creates implicit polynomial, whose equation in barycentric coordinates with respect to points A,B,C is given by the fourth parameter.

Example: TriangleCurve[P,Q,R,(A-B)*(B-C)*(C-A)=0] gives a cubic curve consisting of perpendicular bisectors of all the segments PQ, QR, RP.

Note: The first three points can be called A,B or C, but in this case you cannot use e.g. x(A) in the equation, because A is interpreted as the barycentric coordinate.