"在几何里,没有专为国王铺设的大道。 There is no royal road to geometry. 欧几里得"
"(Euclid) Two unequal magnitudes being set out, if from the greater there be subtracted a magnitude greater than its half, and from that which is left a magnitude greater than its half, and if this process be repeated continually, there will be left some magnitude which will be less than the lesser m"
"连接CD."
"连接DE,且在DE上作一个等边三角形DEF,连接AF."
"令AB是较大的,取BG等于DE;且连接GC."
"There is no royal road to geometry."
"从那么少的几条外来的原理,就能够取得那么多的成果,这是几何学的光荣。 It is the glory of geometry that from so few principles, fetched from without, it is able to accomplish so much. 牛顿《自然哲学之数学原理》序"
"01 /点是没有部分的东西。 Apointis that which has no part. 02 /线是没有宽的长。 Alineis breadthless length. 03 / 线之端是点。 The extremities of a line are points."