What is a parallelogram that does not have a right angle?

Answer 1

A rhombus (UK), or rhomboid (US), is a quadrilateral parallelogram which can have no right angles. An example is the plane shape we refer to as a 'diamond'. A right-angled rhombus is called a square.

If only two sides of the quadrilateral plane figure are parallel, it is called a trapezium (UK), or trapezoid (US). The two sides which are not parallel may or may not be of equal lengths. If their lengths are equal the shape is called an isoscoles trapezium;