diff --git a/CurveComposite.cpp b/CurveComposite.cpp
index 2af9c4f..225e40f 100644
--- a/CurveComposite.cpp
+++ b/CurveComposite.cpp
@@ -292,8 +292,10 @@ CurveComposite::Close( void)
   // se molto vicini li modifico
    if ( AreSamePointEpsilon( ptStart, ptEnd, 10 * EPS_SMALL)) {
      // se un solo arco
-      if ( m_CrvSmplS.size() == 1  &&  m_CrvSmplS.front()->GetType() == CRV_ARC)
-         return GetBasicCurveArc( m_CrvSmplS.front())->ChangeAngCenter( ANG_FULL) ;
+      if ( m_CrvSmplS.size() == 1  &&  m_CrvSmplS.front()->GetType() == CRV_ARC) {
+         CurveArc* pArc = GetBasicCurveArc( m_CrvSmplS.front()) ;
+         return pArc->ChangeAngCenter( pArc->GetAngCenter() > 0 ? ANG_FULL : -ANG_FULL) ;
+      }
      // caso generale
       Point3d ptMid = Media( ptStart, ptEnd) ;
       if ( ! m_CrvSmplS.front()->ModifyStart( ptMid)  ||
@@ -883,8 +885,10 @@ CurveComposite::TestClosure( void)
    // se distanza superiore al limite ridotto forzo i punti a coincidere
    if ( ! AreSamePointEpsilon( ptStart, ptEnd, EPS_CONNECT)) {
      // se un solo arco
-      if ( m_CrvSmplS.size() == 1  &&  m_CrvSmplS.front()->GetType() == CRV_ARC)
-         return GetBasicCurveArc( m_CrvSmplS.front())->ChangeAngCenter( ANG_FULL) ;
+      if ( m_CrvSmplS.size() == 1  &&  m_CrvSmplS.front()->GetType() == CRV_ARC) {
+         CurveArc* pArc = GetBasicCurveArc( m_CrvSmplS.front()) ;
+         return pArc->ChangeAngCenter( pArc->GetAngCenter() > 0 ? ANG_FULL : -ANG_FULL) ;
+      }
      // caso generale
       Point3d ptM = Media( ptStart, ptEnd) ;
       return ( m_CrvSmplS.front()->ModifyStart( ptM)  &&