📜 Theorem, law or theory

Morley's trisector theorem

Teorema de Morley

Date
1899 · confidence high
Place
Haverford, Pennsylvania, United States
Credited to
Frank Morley
Field
Knowledge & symbols

What was discovered

A plane-geometry theorem stating that, in any triangle, the intersection points of adjacent angle trisectors always form an equilateral triangle.

Discovered by Anglo-American mathematician Frank Morley; it has several generalizations producing other equilateral triangles.

What it led to

  • New generalizations in triangle geometry
  • Renewed interest in angle trisection within pure geometry

Built on

  • Classical Euclidean geometry

Links

Sources✓ verified 2026-09-28