Lay down a large piece of paper around the fireplace and cut it to the shape of the fireplace. If the fireplace is large, use several sheets of paper to accomplish this.
Lay down the floor in straight rows until you get to the fireplace.
Lay the first plank that will go around the fireplace on the template and mark the backside of the plank with a dark pencil where it needs to be cut to fit. Remember to allow for the appropriate gap for a floating floor, typically 1/8 inch to 1/4 inch (refer to your manufacturer's instructions).
Cut the plank with the jigsaw along the line you marked on the backside. If you are unsure, cut it a little longer, dry-fit the piece in and then cut small strips around the curve until it fits properly.
Put the piece in place as you have the rest of the floor.
Continue this process for the rest of the floor.