(defun AddSurfPoly2d ( / ss vla cpt scumul)
  ;addition des surfaces des polylignes sans vérification si elles sont closes ou non
  (setq ss (ssget  (list (cons 0 "LWPOLYLINE"))))
  (setq scumul 0 cpt 0)
  (foreach vla (mapcar 'vlax-ename->vla-object (vl-remove-if 'listp (mapcar 'cadr (ssnamex ss))))
    (if (= (vlax-get-property vla 'closed) :vlax-true)
      (setq scumul (+ scumul (vlax-get-property vla 'area))
	    cpt (1+ cpt))
      )
    )
  (if (= cpt (sslength ss))
    (alert (strcat "\nL'addition des aires des " (itoa cpt) " polylignes closes est de : " (rtos scumul) " m˛"))
    (if (= (- (sslength ss) cpt) 1)
      (alert (strcat "\nL'addition des aires des " (itoa cpt) " polylignes closes est de : " (rtos scumul) " m˛\n"
		   "Il y a "(itoa (- (sslength ss) cpt)) " polyligne ouverte"))
      (alert (strcat "\nL'addition des aires des " (itoa cpt) " polylignes closes est de : " (rtos scumul) " m˛\n"
		   "Il y a "(itoa (- (sslength ss) cpt)) " polylignes ouvertes"))  
  )
  )
  )