If you lay tile it is rare to do a job and not have to cut a curved piece of tile. If you do have to cut a curved piece there are two ways to do it. First, you have to draw outline of the cut that you need to make on the tile itself and mark the part you are going to remove with an X. The low tech method involves using a pair of tile nippers. You nip away pieces of the tile until you have nipped away the whole area until you have a circular cut out. For a more polished cut you can use a spiral cutting saw. This saw will cut a nice smooth edge that is ok if the cut is visible.