parallelogram, square, rectangle, rhombus
A square is a shape that has four sides equal in length
the little dash-marks on multiple sides are to show that the two sides are of the same dimension/length.
So, if all four sides are marked as equivalent, this must be a square.
And, a parallelogram is a shape with two pairs of parallel sides, meaning that a square/this shape is a parallelogram
However, a square is also a rectangle, because it is a parallelogram with four 90-degrees (interior) angles [which is just a formal definition for what you know to be a rectangle].
AND a square is a rhombus because it has four sides of equal length
a square is a rectangle; a rectangle is a parallelogram
a square is a rhombus;
a rhombus is a parallelogram; a square is a parallelogram
(and a square is a square)