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Classical Geometry

TRIANGLES

Triangle
Centroid
Centroid
Circumcenter
Incenter
Orthocenter
Euler Line
Gergonne Point
Ceva's Theorem
Ceva's Theorem
Isotomic Conjugate
Menelaus's Theorem
Napoleon's Theorem
Finsler-Hadwiger Theorem
Morley's Trisector Theorem
Viviani's Theorem
Van Aubel's Theorem
Thébault's I Problem
Fagnano's Problem
Droz-Farny Line Theorem

CIRCLES

Inscribed Angle in Circle
Simson Line
Circle Power
Radical Axis
Radical Axis - Pencil of Circles
Radical Center
Circle Inversion
Circle Inversion - Circles and Lines
Circle Polar Line
Circle Polar Line Reciprocity
Exterior Point
Interior Point
Exterior Point - Bitangent Circle
Interior Point - Bitangent Circle
D'Alembert Theorem
Apollonius Tangency Problem
Apollonius Tangency Problem
Apollonius Tangency Problem - 8 circles
Miquel's Theorem
Clifford's Theorem
Five Circles Theorem
Ptolemy's Theorem
Ptolemy's Theorem with an Equilateral Triangle
Equal Incircles Theorem
Three Tangents Theorem
Apollonius Circle
Constant Chord Theorem
Malfatti Circles
Feuerbach's Circle
Deltoid
Deltoid in an Astroid
Nested Hypocycloids
Complementary Hypocycloids

PLANE CURVES

Astroid
Classic Spirals