hello, i have a vertex group containing a 40 degree section of a circle, i would like to duplicate and revolve it around the whole circle ( 9 times ) so it makes a full circle again. i also need it to join up where edges meet if that is possible 
So what you have is a pie slice shape right?
Work these steps in orthographic view. First, place the 3D curser on to the center vertex of circle you want to form; select the vertex, [Shift][S], and pick “Curser to Selected”. Choose 3D curser as a pivot point in the menu bar. Select the vertex to be rotated 40 degrees. [Shift][D] to duplicate it. Click on mouse button to get out of duplication mode with out dragging the new vertex. Hit [R] to rotate, and key in 40. The new vertex will rotate 40 degrees from the center. Repeat until you get all the vertices. Then connect those points to make a face.
You need to add all those new verities in to original vertex group after its all done.