The two classifications of wood are hardwood and softwood.
Two simple classifications of books are fiction and non-fiction.
A polygon can not have a diameter.
Talking about a "2-D polygon" is the same as talking about a "polygon." By definition a polygon is a 2-dimensional figure, so all polygons are 2-dimensional and anything that is not 2-dimensional cannot be a polygon. Of course, not all 2-dimensional figures are polygons.
You might be aware of certain names of special polygons, such as pentagon, hexagon, and octagon. These terms classify a polygon by the number of sides.
Every polygon is 2-dimensional.
Race and Alienage
There is no such thing as a 2-sided polygon.
A vertex of a polygon is where 2 sides meet
A polygon is a 2-dimensional figure.
No, a polygon is a 2-dimensional object.
A quadrilateral is any 4 sided polygon. Therefore, quadrilaterals would include parallelograms, rectangles, squares, complex quadrilaterals as well as trapezium.