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Theorem

Morley's Trisector Theorem

Geometry

The three points of intersection of the adjacent angle trisectors of any triangle always form an equilateral triangle. Discovered by Frank Morley, it is a celebrated example of a simple, surprising fact hidden in elementary geometry.

Facts
Statement
In any triangle, the points where each pair of adjacent angle trisectors meet form an equilateral triangle, called the Morley triangle. 1
Proof Year
1899 1
Classification
Statement Form
Characterization Theorem 1
Connections

In Branch

Sources
1. Morley's Trisector Theorem (Wikipedia)
Wikimedia Foundation
  • lead paragraph, theorem statement sentence
    In plane geometry, Morley's trisector theorem states that in any triangle, the three points of intersection of the adjacent angle trisectors form an equilateral triangle, called the first Morley triangle or simply the Morley triangle.
  • lead paragraph, discovery attribution sentence
    The theorem was discovered in 1899 by Anglo-American mathematician Frank Morley.
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