This paper aims to investigate how Chinese and Korean evaluate $pi$ and measure tile area of circle by reviewing the problems in the old mathematical books. The books are Gu-Jang-San-Sul(The nine chapters on tile mathematical art) for China and Gu-Il-Jib for Chosun Dynasty. The result shows that our ancestors used the different values of ${pi}$ in relation to the accuracy and the various methods for measuring the area of circle.