For #3 I did 2 ways. First I did a net to make my solving easier. For the 1st way I did is multiply lxw to all sides (top,front,side). Then I added all of the answer to get my Total Surface Area or T.S.A. For the 2nd way what I did is I drawed the lateral area then I added the lengths of it example 18.5. After I added it I then multiply it 13.5 because they all share 13.5. Then I multiply the side. Lastly, I added it all to get the T.S.A what I got is 819.5cm²
For #5 I did is I first got the 3 rectangles surface areas. Then I did the triangle's surface area. After that I added all of it to get the T.S.A. (there's a diagram but it got cut off)
What is the total surface area?
For #7 Basically it gave us the surface area of all sides. So you only to multiply each of them to 2 because for example if there's a top there's a bottom. After you multiply each of those add it to get the total surface area.