David Little
Mathematics Department
Penn State University
Eberly College of Science
University Park, PA 16802
Office: 403 McAllister
Phone: (814) 865-3329
Fax: (814) 865-3735
e-mail:dlittle@psu.edu

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Morley's Theorem
Morley's Theorem states that if you trisect the three angles of a triangle, then adjacent trisectors meet at the vertices of an equilateral triangle.

In the Applet below, drag any of the colored dots around to change the shape of the triangle.

Recall that trisecting an angle cannot be accomplished using compass and straightedge constructions. The Applet below trisects the angles by simply dividing each interior angle of the triangle by three.