I've searched around and can't seem to find a solution to what I imagine would be a fairly simple problem. I'm trying to calculate what size a parcel bag I would need to fit in a malleable item, such as a towel.
I'd thought that I could just calculate the volume of the bag sizes, and the volume of the folded towel to determine this, but given the parcel bags are flat, that doesn't seem to work.
For instance, I have a parcel bag which is 26cm * 39cm, and I've given it a height of 1cm, a volume of 1,014cm cubed. My folded towel is 21cm * 28cm * 7cm, giving a volume of 4,116cm cubed. The folded towel fits in the bag, so where have I gone wrong?
Thanks in advance
Welcome to (one of) the disconnect(s) between mathematics/science and real life! You assumed a thickness of the bag of $1$ cm, but why that instead of $1/2$ or $2$ or something else?. I suspect the sides bulged out rather farther than that, increasing the volume. You also measured the towel in an uncompressed state and ignored the fact that the corners were round, not square. The bag and the towel found a compromise volume that suited them both.