Inside a square ABDE, take a point C so
that CDE is an isosceles triangle with angles 15oat D
and E. What kind of triangle is ABC?
|History of the Problem:
This problem was an exercise that was found in the text Introduction
to Geometry by Coxeter. The exploration of the problem's solution
was initially done in Geometer's Sketchpad (GSP). Searching for other
means of a solution, we tried other methods of approaching the problem,
which led us to road blocks! We have two ways to work this problem
and are currently searching for other approaches. Keep checking back
for updates to this page.
Geoff and Rich