\input zb-basic
\input zb-matheduc
\iteman{ZMATH 2014e.00556}
\itemau{Unger, J. Marshall}
\itemti{Kitta's double-locked problem.}
\itemso{Forum Geom. 14, 43-50 (2014).}
\itemab
The paper presents an interesting problem extracted from a Sangaku compilation. Two proofs are given: the particular one which is based on the use of Pythagorean triples and the general one which requires more powerful tools.
\itemrv{Antonio M. Oller (Zaragoza)}
\itemcc{G45}
\itemut{Sangaku; Fujita's mixtilinear circle theorem; Pythagorean triple}
\itemli{http://forumgeom.fau.edu/FG2014volume14/FG201404index.html}
\end