(defun subSEG (ent pt / pam pam1 p1 p2 dis dis1 pv)
  (setq pt   (vlax-curve-getclosestpointto ent pt)
        pam  (fix (vlax-curve-getparamatpoint ent pt))
        pam1 (1+ pam)
        dis  (- (vlax-curve-getdistatparam ent pam1)
                (vlax-curve-getdistatparam ent pam)
             )
        p1   (vlax-curve-getpointatparam ent pam)
        p2   (vlax-curve-getpointatparam ent pam1)
        dis1 (distance p1 p2)
  )
  (if (equal dis1 dis)
    (list '(0 . "LINE")
          (cons "LEN" dis)
          (cons "STP" p1)
          (cons "ENP" p2)
    )
    (list
      '(0 . "ARC")
      (cons "LEN" dis)
      (cons "STP" p1)
      (cons "ENP" p2)
      (cons
        "CEN"
        (polar pt
               (angle (setq pv (vlax-curve-getsecondderiv
                                 ent
                                 (vlax-curve-getparamatpoint ent pt)
                               )
                      )
                      '(0. 0.)
               )
               (distance pv '(0. 0.))
        )
      )
    )
  )
)