# Types of Shapes

Decagon A skew decagon is a skew polygon with 10 vertices and edges but not existing on the same plane. The interior of such an decagon is not generally defined. A skew zig-zag decagon has vertices alternating between two parallel planes.

Dodecagon Regular dodecagon A regular dodecagon is a figure with sides of the same length and internal angles of the same size. It has twelve lines of reflective symmetry and rotational symmetry of order 12.

image: pixshark.com
Heptagon A heptagon is a seven-sided polygon. Along with seven sides, a heptagon has seven vertices and angles. A regular heptagon is a heptagon that has congruent sides and angles.

source: study.com
Hexagon A regular hexagon is defined as a hexagon that is both equilateral and equiangular. It is bicentric, meaning that it is both cyclic (has a circumscribed circle) and tangential (has an inscribed circle).

Nonagon In geometry, a nonagon / ˈ n ɒ n ə ɡ ɒ n / (or enneagon / ˈ ɛ n iː ə ɡ ɒ n /) is a nine-sided polygon or 9-gon. The name "nonagon" is a prefix hybrid formation, from Latin (nonus, "ninth" + gonon), used equivalently, attested already in the 16th century in French nonogone and in English from the 17th century.

Octagon In geometry, an octagon (from the Greek ὀκτάγωνον oktágōnon, "eight angles") is an eight-sided polygon or 8-gon. A regular octagon has Schläfli symbol {8} and can also be constructed as a quasiregular truncated square, t{4}, which alternates two types of edges. A truncated octagon, t{8} is a hexadecagon, t{16}.

Pentagon As you can see from the picture, a pentagon is a closed and flat two-dimensional surfaced shape with five angles and five sides. The word pentagon itself tells you what it is. 'Penta' is the Greek word for five and 'gonia' is the Greek word for angle.

source: study.com
Polygon Polygons A polygon is a plane shape with straight sides. Is it a Polygon? Polygons are 2-dimensional shapes. They are made of straight lines, and the shape is "closed" (all the lines connect up).