van Lamoen
- Apex
- Apollonius Circle
- Archimedean Circle
- Chasles's Polar Triangle Theorem
- Circular Point at Infinity
- Circumcevian Triangle
- Conway Triangle Notation
- Cosine Circle
- Darboux Cubic
- Desmic Mate
- Diagonal Triangle
- Droz-Farny Theorem
- Hinge Theorem
- Isocubic
- Isoscelizer
- Isotropic Line
- Lucas Cubic
- M'Cay Cubic
- Midcircle
- Miquel's Pentagram Theorem
- Miquel Point
- Mixtilinear Incircles
- Morley's Theorem
- Neuberg Cubic
- Nine-Point Circle
- Orthic Axis
- Orthocorrespondent
- Orthodiagonal Quadrangle
- Orthogonal Involution
- Orthologic Triangles
- Orthotransversal
- Pappus Chain
- Parallelian
- Perspector
- Petr-Neumann-Douglas Theorem
- Pivotal Isocubic
- Pivotal Isogonal Cubic
- Pivotal Isotomic Cubic
- Plastic Constant
- Polar Triangle
- Pompeiu's Theorem
- Poristic Triangles
- Proportionally-Cutting Circle
- Ptolemy Inequality
- Reflection Triangle
- Schoch Line
- Self-Isogonal Cubic
- Self-Isotomic Cubic
- Self-Polar Triangle
- Sine-Triple-Angle Circle
- Stammler Circles
- Stammler Triangle
- Stewart's Theorem
- Thébault's Theorem
- Triangle Square Inscribing
- Trilinear Polar
- Trilinear Pole
- Tripolar Coordinates
- Tucker Hexagon
- Tweedie's Theorem
- Unary Cofactor Triangle
- van Aubel Line
- van Aubel's Theorem