They are polygons and its perfectly acceptable to call them 13-agon or a 14-agon... etc but what's more important is knowing how to work out their geometrical properties.
multi sided shapes are called polygons
Equal sided = equilateral.
Hexagons.
Heptagon.
Polygons.
Hexagon
hexagon.
pentagons
3d shapes with six faces are called hexahedra.
No because all 4 sided shapes are called quadrilaterals which includes parallelograms
They are called Quadrilaterals.
Quadrilaterals