A 2D shape with 9 sides is called a Nonagon.
A Nonagon
nonagon
9
-7
A triangle as no other 2d shape can have 3 sides.
The shape of 2D is a flat surface.
A 2D shape that has four sides and is thirteen letters long is a quadrilateral.
Any 4 sided 2D shape
No. A 2d shape is a plane area, which may be regarded as a face, which is bounded by a side or sides.
2d shapes that do not have equal sides do not usually have special names.
A 2D shape with forty sides is known as a tentracontagon.