right angle
A plane is made up of an infinite number of sides (lines) that are joined at endpoints. This creates a flat surface that extends infinitely in all directions. Each side of a plane is defined by two points.
Well a triangle has 3 sides and vertices.
a triangle
Any polygon is.
Any closed polygon could be made using the descriptions above.
A plane figure with eight sides is an octagon.
Spatial figure is a three dimensional figure. It is made up of plane figure whose all sides are joined together to form a close figure
regular polygon-all the sides are the same length and the angles have the same measurement. polygon-a closed plane figure whose sides are segments that intersect at their endpoints.
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.