Quadrilaterals are one type of polygon that has four sides and four vertices and four angles along with 2 diagonals. There are various types of quadrilaterals. Trapezium, kite, square, etc.
Introduction of curves-
A curve is a geometrical figure obtained when a number of points are joined without lifting the pencil from the paper and without retracing any portion. It is basically a need which not to be straight.
The various types of curves are:
Open curve- An open curve is a curve in which there is no path from any of its point to the same point.
Closed curve- This is a curve that forms a path any of its point to the same point.
A curve can be
-a closed curve
-an open curve
-a closed curve which is not simple.
Therefore, Complete step by step answer:
A closed curve whose endpoints join to enclose an area is called closed curves.
They all are known as a closed curve.Note:
In simple closed curves the shapes are closed by line segments or by a curved line.
There are three types of simple closed curves-
Some simple closed curves are made of line segments only. These curved are known as polygons, triangles, etc.
Some simple closed curves are made by curved lines only. A circle is an example of such a closed curve.
Some simple closed curves are made of both line segments and curved lines.