the answer is 8
Square and rhombus.
There are infinitely many 2d shapes. They can have 1 side (a circle or ellipse) to infinitely many. They can have sides that are straight or not, the sides can be equal or unequal in length, the angles can be equal or unequal, etc.
4
No
square
isoceles triandle, square
Square and rhombus.
The only similarities between these shapes are that:These shapes have all congruent interior anglesObviously, the shapes are regular and have equal sides.
There are infinitely many 2d shapes. They can have 1 side (a circle or ellipse) to infinitely many. They can have sides that are straight or not, the sides can be equal or unequal in length, the angles can be equal or unequal, etc.
2d shapes that do not have equal sides do not usually have special names.
Triangles
rectangle
4
A septagon or a heptagon
Hectogon
Squares
2D - Nonagon 3D - Nonahedron