Imperial Siku Quanshu

Euclid's Elements, Volume 6

Written by Matteo Ricci of the West

Proposition 1

Triangles and parallelograms of equal height are to each other as their bases.

A geometric diagram showing two parallel horizontal lines. Between these lines are two triangles (labeled Jia-Yi-Bing and Ding-Wu-Ji) and two parallelograms sharing the same bases and heights. Points are labeled with Celestial Stems: Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin.

Explanation: The two triangles, Jia-Yi-Bing and Ding-Wu-Ji, are of equal height. Their bases are Yi-Bing and Wu-Ji. The two parallelograms, Geng-Wu-Xin and ... text continues to next page