It has 6 possible pairs of sides, although all the pairs will look the same.
It has 6 possible pairs of angles, although all the pairs will look the same.
Two pairs.
Four of them.
23 pairs OR 46.
66
forty eight
2 pairs
23 pairs OR 46.
None
"Dose" is a measured portion of a medicine. I am not aware of any factor pairs related to dose 18 or any other measured quantities of medication!18 does have 3 factor pairs.
A square has 2 pairs of equal opposite parallel lines
One pair.
23 pairs of chromosomes