Why is 36 a square number?

Answer 1

A number is a "square number" if it corresponds to a square arrangement of dots in a regular grid pattern. The first few square numbers are...

1:

.

4: (2 x 2 grid)

. .
. .

9: (3 x 3 grid)

. . .
. . .
. . .


and so on.

36 is a square number because that's how many dots are in a 6 x 6 grid.

. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .