Simple Closed Curves

In simple closed curves the shapes are closed by line-segments or by a curved line.

Triangle, quadrilateral, circle, etc., are examples of closed curves.

$Closed Curves$

A curve which starts and ends at the same point without crossing itself is called a simple closed curve. A circle is a simple closed curve.

Some more examples of simple closed curves are given below.

$Closed Curves Examples$

The shape which is not closed by line-segments or a curve is called an open curve.

$Open Curve$

The curves which do not have same starting and end points are called open curves.

Some examples of open curves are given below.

$Open Curves Examples$

A closed curve which does not cross itself is called a simple closed curve.

The curve which crosses itself is not a simple closed curve.

Here is a collection of closed curves. Except curve (d) and (e), the remaining shapes are simple closed curves.

$Collection of Closed Curves$

There are three types of simple closed curves.

(i) Some simple closed curves are made of line-segments only. These curves are known as polygons. Triangle, quadrilateral, pentagon etc., are polygons.

$Example of Polygons$

(ii) Some simple closed curves are made by curved lines only. A circle is an example of such a closed curve.

$Examples of closed curves are made by curved lines$

(iii) Some simple closed curves are made of both line-segments and curved lines.

$are made of both line-segments and curved lines$

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