A tinsmith wants to make a small windowsill planter from a 55 cm x 25 cm sheet of copper. She'll form it by cutting equally sized squares from each of the four corners of the sheet, folding up the resulting flaps to form the sides of the planter, and then soldering the
four vertical edges. If she wants the ratio of the planter's width to height to be 3, what will be the ratio of its length to width? Write the
exact answer. Do not round.