A twenty sided, 2D figure is called an icosagon.
Decagon. A decagon is the name of a ten sided shape.
A trapezoid has two parallel sides.
A general quadrilateral. No special name.
quadrilateral shape
A square is a four sided shape but generically they are called Quadrilaterals.
Icosikaihenagon
The name of a four sided figure (or shape) is called a Square. :)
The name of a four sided shape that looks like a kite is a diamond.
a quadrilateral
Icosahedron is the shape, but it's just called 20 sided if you want to buy one.
I thing is a heptagon
A rhombus or a parallelogram
a four sided shape.
A regular twenty-sided polygon is called an icosagon.
A twenty sided, 2D figure is called an icosagon.
irregular quadrilateral