Martha Stewart is designing a box for her cat to sleep in.

Last updated: 8/11/2022

Martha Stewart is designing a box for her cat to sleep in. It has 4 sides and a bottom but no top. The plush material for the square bottom of the box costs $18/ft² and the material for the sides costs $12/ft². She needs a box with a volume of 18 ft^ 2. Find the dimensions of the box that minimize the cost.