A non-rectangular parallelogram
A square. Its opposite sides are equal and it has 4 right angles.
Rectangle
The shape you are describing is a rhombus. A rhombus has all four sides of equal length, opposite sides that are parallel, and opposite angles that are equal. When the diagonals of a rhombus are drawn, they intersect at right angles.
a rectangle does not have four equal sides and its opposite sides are equal and has four right angles
Rhombus
Rhombus!
rectangles squares
rhombus
A rhombus has 4 sides of equal length, opposing parallel sides, and no right angles
A rhombus
A rhombus
a parallogram