Best way to draw an array of objects

yes i just also spotted the problem Image may be NSFW.
Clik here to view.

now this is working

poly.arc(0, 0, radius, radius, 0, 360);

for(int i=0; i<poly.getVertices().size(); i++){
    mesh.addVertex(poly[i]);
    mesh.addVertex(poly[i+1]);
    mesh.addVertex(ofVec3f(0,0));
}

Now for my personal knowledge, i wanted to know why this one wouldn't work

path.arc(0, 0, radius, radius, 0, 360);
mesh = path.getTessellation();

seems like ofPolyline and ofPath create an arc the same way but i can't find the way to "re-organize" the tessellation the way i want it to be drawn