Five equilateral triangles covertically placed would stand on a pentagonal base, and it was found that, by forming several sets of such pyramids, a solid could be obtained which had zo triangular faces, which met in pairs to form 30 edges, and in fives to form 12 vertices.
It has 12 pentagonal faces, and 30 edges, which intersect in fives to form 12 vertices.
Finger-counting is of course natural to children, and leads to grouping into fives, and ultimately to an understanding of the denary system of notation.
The flowers are hermaphrodite and regular with parts in fives (pentamerous) throughout, though exceptions from the pentamerous arrangement occur.
Ten is two fives, 15 three fives, 20 is a "man" (ten fingers and ten toes), 100 is "five men," and so on.