The following shape has three sides and the only angles are right angles. ----- | |___
The shape you are looking for is a quadrilateral. If you have a square, all angles MUST be right angles. A parallelogram can also have 4 equal sides in length and parallel sides, but a parallelogram doesn't have right angles.
A shape with opposite sides parallel and of the same length and four right angles is a rectangle.
A rectangle has 4 sides not the same length and 4 right angles.
Its a diamond :]
its a rhombus