Meaning of pons asinorum

pons' as•i•no'rum

Pronunciation: (as"u-nôr'um, -nōr'-), [key]
  1. a geometric proposition that if a triangle has two of its sides equal, the angles opposite these sides are also equal: so named from the difficulty experienced by beginners in mastering it. Euclid, 1:5.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.