If a recipe calls for 3 1/2 cups of flour, how much flour will be needed if the recipe is tripled?

Change the mixed number into an improper fraction and then multiply it by 3
7/2 x 3= 21/2= 10.5

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's