272. The Artist's Puzzle. An artist decided to purchase a canvas for a miniature, the area of which should be 72 cm $^{2}$. To stretch the miniature on a stretcher, there should be strips of clean canvas 4 cm wide at the top and bottom, and 2 cm wide on the sides.

What are the smallest dimensions of the required canvas?
272. The canvas should be \(10 \times 20\) cm in size, the width of the miniature will be 6 cm, and the height 12 cm. It is easy to verify that the excess will be as required by the condition of the problem.