祖冲之
Liu Hui's algorithm was one of his most important contributions to ancient Chinese mathematics. It was based on calculation of -gon area, in contrast to the Archimedean algorithm based on polygon circumference. With this method Zu Chongzhi obtained the eight-digit result: 3.1415926 &lt; &lt; 3.1415927, which held the world record for the most accurate value of for 1200 years, even by 1600 in Europe, the Dutch mathematician Adriaan Anthonisz and his son obtained value of 3.1415929, accurate only to 7 digits.