\input zb-basic
\input zb-matheduc
\iteman{ZMATH 2013a.00618}
\itemau{Barkan, Stanley}
\itemti{If not, then what if as well? Unexpected trigonometric insights.}
\itemso{Math. Enthus. 9, No. 1/2, 19-36 (2012).}
\itemab
Summary: In performing an exercise of ``what if not", one can end up with a paucity of structure. Adding alternative structure can be a rich source of discovery, as we present here. The framework of this presentation is the original voyage of discovery, from a trivial geometric problem to the derivation of some unexpected trigonometric formulae based on regular polygons. The original ``voyage" has been changed only sufficiently to make the text readable.
\itemrv{~}
\itemcc{G60}
\itemut{trigonometric identities; problem posing; Euclidean geometry}
\itemli{}
\end