Chapter - 4 - EXERCISE 4.2 - Playing with Numbers (NCERT Class 6th Maths Solution)

1. Classify the following curves as (i) Open or (ii) Closed.



Solution/Explanation:

An open curve is a curve where the beginning and end points are different.

A closed curve  is a curve that joins up so there are no end points.

(a) Open

(b) Closed
(c) Open
(d) Closed
(e) Closed.

2. Draw rough diagrams to illustrate the following : (a) Open curve (b) Closed curve.

Solution/Explanation:

(a) Open Curves: Curves whose end points do not meet are called open curves.

(b) Closed curves: Curves whose end points join to enclose an area are called closed curves.

Open Curves:
Closed Curves:

3. Draw any polygon and shade its interior.

Solution/Explanation:

A polygon is a n-sided two-dimensional figure, where n is the number of sides. Here, a pentagon is shown which as 5 sides.

4. Consider the given figure and answer the questions : (a) Is it a curve? (b) Is it closed?

Solution/Explanation:

(a) Yes it is a curve.

(b) Yes it is closed.

5. Illustrate, if possible, each one of the following with a rough diagram: 
(a) A closed curve that is not a polygon. 
(b) An open curve made up entirely of line segments. 
(c) A polygon with two sides.

Solution/Explanation:



(a) A closed curve that is not a polygon. 




(b) An open curve made up entirely of line segments. 

(c) It is not possible to have a polygon with two sides.