A Principal Vertex of a Simple Polygon is called an ear if the diagonal
that bridges lies entirely in . Two ears and are said to overlap if

The Two-Ears Theorem states that, except for Triangles, every Simple Polygon has at least two nonoverlapping ears.

**References**

Meisters, G. H. ``Polygons Have Ears.'' *Amer. Math. Monthly* **82**, 648-751, 1975.

Meisters, G. H. ``Principal Vertices, Exposed Points, and Ears.'' *Amer. Math. Monthly* **87**,
284-285, 1980.

Toussaint, G. ``Anthropomorphic Polygons.'' *Amer. Math. Monthly* **122**, 31-35, 1991.

© 1996-9

1999-05-25