  This paper demonstrates how a nineteenth century Japanese votive temple
problem known as a sangaku from Okayama prefecture can be solved using
traditional mathematical methods of the Japanese Edo (1603-1868 CE). We compare
a modern solution to a sangaku problem from Sacred Geometry: Japanese Temple
Problems of Tony Rothman and Hidetoshi Fukagawa with a traditional solution of
\=Ohara Toshiaki (?-1828). Our investigation into the solution of \=Ohara
provides an example of traditional Edo period mathematics using the tenzan
jutsu symbolic manipulation method, as well as producing new insights regarding
the contextual nature of the rules of this technique.
