Quadrilateral > Parallelogram > Square
A square is a quadrilateral / parallelogram that has ALL FOUR (4) EQUAL SIDES with FOUR (4) RIGHT ANGLES (90°).
A right angle is an internal angle which is equal to 90°.
NOTES:
It is helpful to think of a SQUARE as a perfect RECTANGLE because it has four (4) sides that are equal.
AreaSquare = S2 or S x S
NOTE: S represents the length of any side of a square since they are all equal.
If you place a SQUARE inside of a box (a square), you get a square. It's like placing a square peg in a square hole. Wow!!! Spell it backward: Wow
KEY: Since a square is a perfect box or a perfect rectangle, instead of having to learn another formula (AreaSquare = S2), simply use the rectangle formula in its place.
A square with a side of 4 in has an area of:
AreaSquare = 4 in x 4 in = 16 in2
REFERENCE: See screenshots above for graphic representations.
To help you remember the difference between a square and a rectangle, remember that a square has ALL four equal sides; whereas, a rectangle normally has two pairs of sides that are not equal.