Paper bag problem
In geometry, the paper bag problem or teabag problem is to calculate the maximum possible inflated volume of an initially flat sealed rectangular bag which has the same shape as a cushion or pillow, made out of two pieces of material which can bend but not stretch. According to Anthony C. Robin, an approximate formula for the capacity of a sealed expanded bag is: V = w 3 ( h / ( π w ) − 0.142 ( 1 − 10 ( − h / w ) ) ) , {\displaystyle V=w^{3}\left(h/\left(\pi w\right)-0.142\left(1-10^{\left(-h/w\right)}\right)\right),} where w is the width of the bag (the shorter dimension), h is the height (the longer dimension), and V is the maximum volume.