To fit correctly measure the width of the window plus 30/40cm (12-16), this will ensure your curtains will comfortably cover your window. Fit your track or pole approximately 15cm (6) above your window recess and centre ensuring you have 15-20cm (6-8) either side of the window.
A keg is a fancy version of your basic barrel. In the factory, a sheet of stainless steel is rolled into a cylinder and welded together. Then, at the cylinder's midpoint, a set of ribs is pressed into it for added rigidity. Next, top and bottom steel plates are stamped out and likewise welded into place.
Background Information: Gummy Bears are made of gelatin, starch, and sugar. Gelatin is a polymer (huge molecule made of many repeating units) that forms large three-dimensional matrices which give structural support to jellies and jams, and lots of other things that you use every day.