Billie wants to make a CD box open at the top The box needs a base 13cm by 200cm and is to be 15cm high How much wood should billie buy?

To determine how much wood Billie needs, calculate the surface area of the open-top box. The base area is 13 cm by 200 cm, which is 2,600 cm². The four sides have a total area of (2 * 15 cm * 13 cm) + (2 * 15 cm * 200 cm) = 390 cm² + 6000 cm² = 6,390 cm². Adding the base area, the total surface area is 2,600 cm² + 6,390 cm² = 8,990 cm². Billie should buy wood that covers at least this area.