Napoleon's Theorem: Mathematics, Equilateral Triangle, Centroid,

Morley's Trisector Theorem: Plane Geometry, Triangle, Equilateral Triangle

Euler Line: line, Geometry, Leonhard Euler, Line (geometry), triangle, Equilateral Altitude (triangle),...

Pappus's Centroid Theorem: Theorem, Surface Area, Revolution

Pappus''s Centroid Theorem: Theorem, Surface Area, Volume, of Revolution