In part A the answer is 13 cm. It shows it right there. Part B is a bit confusing, but I will try. Since the height of the candy box is 13 cm, and the width of it is 10 cm, do 13 x 10 and you get 130. That's for one side. The length for the other side is 20, so do 13 x 20 which equals 260. Hope this helps