Use cosine rule and sine rule
The method should be to a<span>ssign numbers to each patient and then use a random number generator to choose one hundred patients to survey. </span>
Check the picture below.
notice, the gift box is just 6 rectangles stacked up to each other at the edges,
left and right, two rectangles of 32x40
top and bottom, two rectangles of 25x32
front and back, two rectangles of 25x40
so, just get the area of all 6 rectangles, add them up, and that's the "surface area" of the rectangular prism, and that's how much paper will be needed to cover it.
I think that you multiply 2 with 4 to get 8 and then multiply 8 with 7 to get that number then add 2.75... to get the total.
Hope it helped..