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c21 Points whose reflections on the altitudes form a triangle perspective with ABC
c22 Points being the ninecenter of their pedal triangle
c23 Points being the orthocenter of their cevian triangle
c24 Deltoids inscribed in a triangle ABC
c25 Inscribed square with a side on BC
c26 Triangle given the vertex A, the circumcenter O and the symmedian point K
c27 Triangle given the circumcenter O, the foot Ha of the A-altitude and the foot Wa of the A-bisector
c28 Triangle given the vertex A, the incenter I and the centroid G
c29 Triangles with given circumcircle c and with a given point N in c as ninecenter
c30 Triangle given the centroid G, the line r containing BC, a point N in AC and a point L in AB
c31 Point P with Simson line parallel to a given line r
c32 Point P with given Steiner line r
c33 Triangle given the A-median m, the A-bisector d, and the product bc of the sides 
c34 Circle through A tangent to BC and cutting equal segments in AB and AC
c35 Given two circles through A, tangents to BC at B and C, construct a third circle tangent to the former and to BC
c36 Triangle with a symmedian orthogonal to the Euler line
c37 Triangle given the incenter I, the centroid G and the orthocenter H
c38 Triangle given the angle A, the A-bisector d, and the sum b+c of the sides
c39 Points of the circumcircle with Simson line through a given point P
c40 Lines with a given orthopole P