What is an 11 an d 12 sided shape called?

Polygon names Name Sides :

henagon (or monogon) 1

digon 2

triangle (or trigon) 3

quadrilateral (or tetragon) 4

pentagon 5

hexagon 6

heptagon 7

octagon 8

enneagon (or nonagon) 9

decagon 10

hendecagon 11

dodecagon 12

tridecagon or triskaidecagon 13

tetradecagon or tetrakaidecagon 14

pentadecagon (or quindecagon) or pentakaidecagon 15

hexadecagon or hexakaidecagon 16

heptadecagon or heptakaidecagon 17

octadecagon or octakaidecagon 18

enneadecagon or enneakaidecagon or nonadecagon 19

icosagon 20

icosihenagon 21

triacontagon 30

tetracontagon 40

pentacontagon 50

hexacontagon 60

heptacontagon 70

octacontagon 80

enneacontagon 90

hectagon (also hectogon) 100

chiliagon 1000

myriagon 10,000

decemyriagon 100,000

A 11 sided shape is a hendecagon right what do you think is a 12 sided shape?

12 Sided Polygon

a 12 sided shape is a dodecahedron or a dodecagon and a 11 sided shape is a hendecahedron

I have 3 closed shapes.All together they have 12 sides and 12 vertices.What shapes do I have?

An 11 sided shape (polygon) is called a hendecagon.

A 12 sided polygon is a dodecagon.

While there are ways to construct a regular dodecagon using compass and straightedge (the classical tools) no similar formula exists for constructing a regular hendecagon.

hendecagon 11

dodecagon 12

11 Sided Polygon

12 sided is called a dodecagon

If your shapes are two dimensional (i.e. planar), see the long list above in another answer.

If, however, your shape is three-dimensional, here's a list of them.

3D (volumetric) shapes :

tetrahedron 4

pentahedron 5

hexahedron 6

heptahedron 7

octahedron 8

nonahedron 9

decahedron 10

hendecahedron 11

dodecahedron 12

triskaidecahedron 13

tetrakaidecahedron 14

pentakaidecahedron 15

hexakaidecahedron 16

heptakaidecahedrono 17

octakaidecahedron 18

nonadecahedron 19

icosahedron 20

nonagon is 9 sides and decagon is 10 sides right