Cube (algebra) the last two digits, "any" pair of digits with the last digit odd can be a perfect cube. With even cubes, there is considerable restriction, for only 00, 2, 4, 6 and 8 can be the last two digits of a perfect cube (where stands for any odd digit and for any even digit). Some cube numbers are also square numbers; for example, 64 is a square number and a cube number . This happens if and only if the number is a perfect sixth power (in this case 2). The last digits of each 3rd power are: It is,
Square root of 5 of a side located on one the faces containing that vertex and opposite to it, are in the ratio This follows from the geometrical relationships between a cube and the quantities (edge-to-face-diagonal ratio, or distance between opposite edges), (edge-to-cube-diagonal ratio) and (the relationship just mentioned above). A rectangle with side proportions 1: is called a "root-five rectangle" and is part of the series of root rectangles, a subset of dynamic rectangles, which are based on and successively constructed using the diagonal of the previous root rectangle, starting from a square. A root-5 rectangle is particularly notable in that it can