A survey of geometrical diagrams in korean mathematical texts from the 17th to the 19th Century

In this paper, geometrical diagrams in Korean mathematical texts from the 17th to the 19th century are collected, analyzed, and compared with those in certain Chinese sources. Several groups of commonly drawn diagrams are represented. Two special features - using the color black to show the "void" or the redundant parts in a diagram and using parallel lines to represent "depth" - are discussed. From the diagrams and special features, it can be seen that diagrams in Korean texts are typically used in three ways: to show manipulations of instruments in the process of problem solving, to explain procedures or algebraic identities, and simply to represent two- or three-dimensional geometrical objects. The last way is different from the ways in which most diagrams are used in Chinese texts.