## twilaswift 2 years ago Use the figure below to answer parts a and b. Kelsey is making a paperweight as a birthday present for her dad. She cut a piece of wood in the shape of a rectangular prism. a. Find the surface area of the prism using the formula SA = 2LW + 2WH + 2LH. Be sure you show all your work. b. Suppose Kelsey wants to decorate the paperweight. What useful information does the surface area provide?

1. twilaswift

2. Directrix

@twilaswift Use the diagram to designate the measures of L, W, and H. Let L = 7 and W = 6 and H = 2 Then, those values will be substituted into the given formula: SA = 2LW + 2WH + 2LH Okay, so far? Yes or No. Feel free to ask questions.

3. bloodrain

Surface area is the outside area of a prism. The wood is 7*6*2. What you need to do is find the area of all sides and add them together. 7*6=42. There's two sides with that area, so multiply by 2, and you get 84. 7*2=14, and there's two sides with that area, so multiply by 2 again and get 28. Now 6*2=12, times 2 again and it is 24. Now that you found the sides, add them together for the answer. 84+28+24 Don't forget to add the unit (in^2) Thinking logically, the surface area indicates how much of something she can wrap around the paperweight or how much paint she can use, etc.

4. twilaswift

136

5. bloodrain

yesh :D