You don’t need a special ruler to make carrots. Cut out a circle and cut it in half. See how much of the 1/2 circle you need to make a cone shape, maybe 1/4? Cut the top of the shape straight and sew up the side of the cone, turn it right side out and run a row of gathering stitches around the top edge. Stuff the carrot and put greens in the top as you gather the top around them and sew to secure.