Typo

Doc/Sd1/inheritance.xml

@@ -41,7 +41,7 @@
               <para>Our two geometric primitives circle and rectangle will
               need a reference point (x,y) in order to allow for
               <methodname>move(...)</methodname> operations. We choose the
-              left lower corner for rectangles and the center for
+              center of gravity for rectangles and the center for
               circles:</para>
 
               <mediaobject>