Japanese mathematician
Arima Yoriyuki
Arima Yoriyuki (有馬 頼徸, December 31, 1714 – December 16, 1783) was a Japanese mathematician of the Edo period. He was the lord of Kurume Domain.
He approximated the value of
and its square,
. In 1766, he found the following rational approximation of
, correct to 29 digits:[1][2]
![{\displaystyle \pi \approx {\frac {428224593349304}{136308121570117}}=3.14159265358979323846264338327(569...).}](https://wikimedia.org/api/rest_v1/media/math/render/svg/89fa0a5a51ece85e83268da3c2e1721e65912f4b)