I have been thinking a lot about a recent interaction on Twitter and how teachers calculate the surface area of a prism. I really liked the idea of looking at the areas of the cross sections (especially as it linked to volume of a prism) and adding the area of the net of the “tube” so, multiplying the perimeter of the cross section by the length. I have played around with a similar format I used for surface area recently and it worked well but I think I like to now move the students to using this approach. Plus I’d like them to practice volume alongside surface area so they can distinguish the two.
I made this after speaking to @MRSEVCartwright
Thanks to @mathsteacher09 for the suggestion of using circles not side elevation images for the area of the cross section