A cube is the 3 dimensional form of a square, each side is of equal length and each face angle at the corners is 90° i.e. adjacent faces
The type of triangle is pretty clear but have please a look at ry1 .
Corner is used here in the sense of "the place at which two converging lines meet". Vertex should be the term.
The area of a surface is 1 unit square . There are 6 of them.
Both have 6 faces but ... .
Try first and if you happen to find a number below 10 or above 12, look at the references given .
Each surface hes 2 diagonals and there are ... volume diagonals .
It has 2 bases .
Regarding the controversy on the number of bases look please at Ref.-Bases . In short :It has 6 potential bases as it floats. It is not easy to
speak about floating objects, so we put it on a base in an orientation (say coordinate system or a room). Bottom and top are given equal rights to be bases. It could only be
the bottom. Do not give much weight to this, there is controversy but it is not important.
Definition (of volume of a cube): The number of cubic units that will exactly fill a cube.
To look for unit spheres would certainly be tedious .
1 side is 4 units of length .
We call them a liter but no unit of measurement can be exact and infinitely accurate, it must have a finite accuracy .
They are mostly out of glass or sheet of metal .
Easy to guess .