$pi <- a hidden id in mirc return the pi number.

3.14159265358979323846

xD

;- prop's
;         cir ->  with a diameter get a perimeter of a circle (diam)
;         rad -> with a radius get a perimeter of the diameter
;         sqr -> perimeter of a square with a side.
;- no prop -> get any perimeter of a polygon.
;-  - - - - - - - -  by dashh xD

alias perimeter {
  if ( $prop = cir ) { return $calc($1 * $pi) }
  if ( $prop = rad ) { return $calc((2 * $pi) * $1) }
  if ( $prop = sqr ) { return $calc(4 * $1 ) }
  return $calc($replace($remove($1-,+,-),$chr(32),$chr(43)))
}