i am installing a circle kit on a slope. one side will have a celtic wall to level the area out. my pavers will come butt up to the top caps on the circle kit. What is the best way to make sure that the radius of the wall top caps match exactly the radus of the circle kit. There has to be a better way than i am currently having to do. i have a pipe driven in where my circle is and i am using a string to mark my arc for my walls. The problem is that this is not really as precise as i need it to be.