shù huà > liǎng diǎn jiān gōng shì
mùlù
No. 1
  shè p1( x1, y1)、 p2( x2, y2),
   p1p2╫ = [( x1-x2) ^2+( y1-y2) ^2]=√ (1+k2)╫ x1-x2╫,
   huò zhě╫ p1p2╫ =╫ x1-x2╫ secα=╫ y1-y2╫ /sinα,
   zhōng α wéi zhí xiàn p1p2 de qīng xié jiǎo, k wéi zhí xiàn p1p2 de xié shuài
No. 2
  zài píng miàn nèi :
   shè A( X1, Y1)、 B( X2, Y2),
   AB∣ =√ [( X1-X2) ^2+( Y1-Y2) ^2]=√ (1+k2)∣ X1-X2∣,
   huò zhě∣ AB∣ =∣ X1-X2∣ secα=∣ Y1-Y2∣ /sinα,
   zhōng α wéi zhí xiàn AB de qīng xié jiǎo, k wéi zhí xiàn AB de xié shuài
   zài kōng jiān zhōng :
   shè A( x1,y1,z1) ,B( x2,y2,z2)
  |AB|=√ [(x1-x2)^2+(y1-y2)^2+(z1-z2)^2)]
   zhèng míng hěn jiǎn dān , tào yòng liǎng gòu dìng
yīngwénjièshì
  1. :  Liangdian spacing away equation