It has 14 sides! The regular polygon with 14 sides is called a tetradecagon.
None.
A decagon is a 10 sided polygon
65
If you say this shape is 18 sided i would guess it has 18 sides. ;)
5 pairs of parallel sides.
A regular decagon, or 10-sided polygon, has interior angles of 144
It is a six sided regular hexagon.
A pentagon (five sided regular polygon) has interior angles of 108°.
360 ÷ 72 = 5, so that the regular polygon is a pentagon (a five-sided polygon).
10 lines. Regular polygon of "x" sides has "x" Lines of Symmetry
12Infinitely many all different:As it is only the area that matters, the perimeter can be any shape:An equilateral triangle (with sides approx 3.398 units)A square (with sides approx 2.236 units)A regular pentagon (with sides approx 1.705 units)A regular hexagon (with sides approx 1.387 units)A regular heptagonA regular octagonA regular nonagonA regular decagonA regular hendecagon (11 sided polygon)A regular dodecagon (12 sided polygon)A regular triskaidecagon (13 sided polygon)A regular 14 sided polygonA regular 15 sided polygonA regular 16 sided polygon...A circle (with radius approx 1.262 units)And there are also the non-regular shapes, eg an L shaped hexagon, a kite, a parallelogram which can have an area of 5 square units.