distpl:ֱߵľ I
distpl2:ֱߵľ II
lineonpnt:ֱͨ I
lineonpnt2:ֱͨ II
par1:ƽ I
par2:ƽ II
parm2eq:̻һ㷽
perp1:ֱ I
perp2:ֱ II
pnt2eq:2 
pntonline:ֱ I
pntonline2:ֱ II
slope2eq:б
