Do parallelograms have to be squares?

Answer 1

No.

Parallelograms have two pairs of parallel opposite sides; they do not have to be the same length.

The opposite angles of a Parallelogram are equal; they do not have to be 90o

A square is required to have all sides equal (opposite sites will be parallel) and all angles 90o (opposite angles are the same)

Thus all squares are parallelograms, but only some parallelograms are squares.

A rhombus is a parallelogram which has all sides the same length.