5-Con trianglesW
5-Con triangles
AA postulateW
AA postulate
Ailles rectangleW
Ailles rectangle
Barycentric coordinate systemW
Barycentric coordinate system
CircumgonW
Circumgon
Congruent numberW
Congruent number
Isogonal conjugateW
Isogonal conjugate
Johnson circlesW
Johnson circles
Orthocentric systemW
Orthocentric system
Perspective (geometry)W
Perspective (geometry)
Similarity (geometry)W
Similarity (geometry)
Sum of angles of a triangleW
Sum of angles of a triangle
Trilinear coordinatesW
Trilinear coordinates