Surface Area


New member
Feb 19, 2021
Hello everyone! Thank you so much for helping! I'm having an issue with this question about surface area. I did one very similar to this one and got it correct, however I am coming up with every number BUT the correct one. I have redone this question about 5 times and I keep coming up with different answers. My text book says the answer should be 121cm. Please refer to the photos posted for my work and the question itself. Thank you all again! For reference, the top question in the first photo is the one I (supposedly) got correct. All the others are failed attempts. I did try to rearrange the shape in order to see if that would help but it did not. I also apologize for how it gets quite hard to read as I was getting frustrated and just trying different ideas. (I also messed up the one after with the two cylinders but I haven't tried it again! Incase you have a keen eye)



Elite Member
Nov 12, 2017
Why don't I see the problems for which you show work on the page from the book?

It will be a lot easier to help you if you can make it clear what problem you are solving, what work applies to that problem, and what the supposedly correct answer is for that problem. What you've done here is somewhat analogous to tossing a pile of random paper at a tax preparer and telling him to find the information he needs. (And he'd be paid.)

I've looked only at the first page of work. There is at least one major error on the middle problem:


It is not true that \(\pi+2\pi\times 4 = 3\pi\times 3\). Check the order of operations!