Question

What are examples of simple closed curves from the below options.
(A) Circle
(B) Rectangle
(C) Square
(D) All of the above

Answer 1

Hint: We are given some options and we have to find whether they are a simple closed curve firstly we will understand some terms to find this.
Closed figures: Figures in which initial and endpoints coincide with each other are called closed figures examples circles and pentagon.
Open figures: Figures with different initial and endpoints are called open figures.
Simple closed figures having three or more line segments are called polygons. Polygon is further divided into various categories depending upon the line segments they have
- A three-sided polygon is called a triangle as shown in the below figure.

- A four-sided polygon is called a quadrilateral as shown in the below figure.

A five-sided is called a pentagon as shown in the below figure.

Complete step by step answer:
Step1: Now we will consider each curve and find whether it is a simple closed curve or not. Some simple closed curve made up of line segments only these curves are known as polygons. Triangles quadrilateral Pentagon are polygons. Hence here square and triangle both are simple closed curve made of line segments only and do not cut themselves
Step2: Now we will consider the curve circle in this case some simple closed curves are made by lines only. A Circle is an example

Final answer: hence option (D) is correct.

Note:
Students mainly get confused in a closed curve and simple closed curve but they should understand the difference between the two so that there will be no mistake in identifying the simple closed curve.
We can differentiate it simply as in a closed curve the shapes are closed by a line segment or by a curve. While the closed curve which does not cross itself is called a simple closed curve