Figure 1

Take any triangle. Mark the 3 points which are the
intersections of adjacent angle trisectors. No matter
what triangle you start with, these 3 points will form
an equilateral triangle!
Presentation Suggestions:
Draw a picture and invite students to draw their own
triangle on a sheet of paper and follow along.
The Math Behind the Fact:
This is yet another surprising fact from
geometry. Can
you think of a proof?
How to Cite this Page:
Su, Francis E., et al. "Morley's Theorem."
Math Fun Facts.
<http://www.math.hmc.edu/funfacts>.
