, Oswald2024-09-042024-09-042004-06-01Teaching Mathematics and Computer Science, Vol. 2 No. 1 (2004) , 49-651589-7389https://hdl.handle.net/2437/379522In real projective geometry of triangles two problems of collinear points are discussed. The problems differ only from the running through the vertices of a given triangle ABC. Resolving the problems we find two cubic curves kS and kT . Affine specialization leads to the circumscribed Steiner ellipse about the triangle ABC and shows us this ellipse in more general surroundings. Euclidean specialization leads to Steiners three-cusped hypocycloid.application/pdfprojective geometry of trianglesplane cubicscircumscribed Steiner ellipse about a triangleSteiners hypocycloidfolyóiratcikkOpen AccessOswald Gieringhttps://doi.org/10.5485/TMCS.2004.0039Teaching Mathematics and Computer Science12Teach. Math. Comp. Sci.2676-8364