Abstract: A cup is made from sheet material. The cup has two opposite side sections for forming a cylinder with one of a gutter-like and spout-like shape in an open state of the cup, a rectangular including square bottom for serving as a base for the cup in the open state of the cup, and folding lines in the side sections that form sides and bases of two isosceles triangles. The folding lines that form the bases of the two isosceles triangles form two of four edges of the bottom. A central folding line in the bottom is parallel with the other two of the four edges of the bottom and runs along a center line of the bottom, connects to the folding lines of the bases of the two isosceles triangles and continues up along the perpendicular of the two isosceles triangles and the side sections to a rim of the side sections and cup. This divides the side sections into pairwise congruent surfaces with insides that bear upon each other when the cup is in a collapsed state.