Xu Guangqi’s Preface
The Jihe Yuanben can be called the pleasure-garden
of the myriad forms,
the Erudite Ocean of the
Book 1, Def 1.
A point is that which has no part.
Book 1, Def 2
A line is a breadthless lenght
right-angled triangles the square on the side subtending
the right angle is equal to the squares on the sides containing the
a given circle to inscribe an equilateral and equiangular