trapezoid
There is no specific name for such a shape.
Trapezium
It it called a trapeziumor a Square
A rectangle is not a square because a square is a shape with 4 equal sides that are parallel, however a square is a rectangle because a rectangle is a shape with 2 pairs of parallel lines, which a square has.
trapezoid
Trapezium (Uk English)
A shape with 4 straight lines in which there are 2 parallel and 2 unparallel lines is called a Trapezium.
A trapezoid perhaps?
A right trapezium.
The four sided shape that has two parallel lines is called a trapezoid. A parallelogram is a four sided shape that has two pairs of parallel lines.
quadrilateral
paralellogram
A regular octagon.
parallelogram
square
Trapezoid