It's called an Octagon.
If they are straight sides, then a polygon. Otherwise, simply "a closed plane figure with 3 or more sides".
hendecagon
I guess it is a dice or what else is it supposed to be? A hexagon is a plane figure with 6 sides.
A polygon is a plane figure with 3 or more straight sides and angles. A plane figure is a flat enclosed figure made of straight lines, curved lines, or both.
An octagon is a plane figure. It has eight sides, but no real base.
A two-dimensional figure is a polygon. The eight sides means that it uses the prefix octa- (meaning eight) to form the name octagon.
It's called an Octagon.
A quadrilateral is a closed plane figure with four straight sides.
If they are straight sides, then a polygon. Otherwise, simply "a closed plane figure with 3 or more sides".
its self because a plane figure is a figure that is flat and has all strait sides.
An 8-sided plane figure is an octagon.
circle
Because an "octagon" is defined as a closed plane figure with 8 vertices which is bounded by straight lines. It must, therefore, have eight sides.
No plane figure has four vertices unless it has four sides.
hendecagon
None. A figure must have more sides than angles.