yes, thanks I found it. it is in the curve level. can we perform a mathematical expression to get the length of the curve? to show in an intelligent text?
var !cur coll all curve for ce
do !i val !cur
$!i
var !cpos cpos wrt/*
!poscur = !!ce.pos.wrt(worl)
prev
!posp1 = !!ce.pos.wrt(worl)
$!i
next
!posp2 = !!ce.pos.wrt(worl)
var !h1 const dist $!posp1 to $!posp2
var !h2 const dist $!posp1 to $!poscur
!dlhor = (2 * $!h2) + ((1 / 3) * ((2 * $!h2) - $!h1))
!dd = !dlhor.string('d2')
$P Length of arc = $!dd
enddo