# RD Sharma Solutions for Class 8 Chapter 15 Understanding Shapes- I (Polygons)

In this chapter, we provide RD Sharma Solutions for Class 8 Chapter 15 Understanding Shapes- I (Polygons) for English medium students, Which will very helpful for every student in their exams. Students can download the latest RD Sharma Solutions for Class 8 Chapter 15 Understanding Shapes- I (Polygons) pdf, free RD Sharma Solutions for Class 8 Chapter 15 Understanding Shapes- I (Polygons)s book pdf download. Now you will get step by step solution to each question.

### Access answers to Maths RD Sharma Solutions For Class 8 Chapter 15 Understanding Shapes- I (Polygons)

EXERCISE 15.1 PAGE NO: 15.5

1. Draw rough diagrams to illustrate the following:
(i) Open curve
(ii) Closed curve

Solution:

Here is the illustration of

(i) Open curve

(ii) Closed curve

2. Classify the following curves as open or closed:

Solution:

(i) Open curve

(ii) Closed curve

(iii) Closed curve

(iv) Open curve

(v) Open curve

(vi) Closed curve

3. Draw a polygon and shade its interior. Also draw its diagonals, if any.

Solution:

Here is the polygon with diagonals and with its interior shaded.

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

Solution:

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

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

(iii) A polygon with two sides.

A polygon with two sides is not possible because, a polygon should have minimum three sides.

5. Following are some figures: Classify each of these figures on the basis of the following:

(i) Simple curve (ii) Simple closed curve (iii) Polygon

(iv) Convex polygon (v) Concave polygon (vi) Not a curve

Solution:

(i) It is a Simple Closed curve and a concave polygon. This is a simple closed curve and as a concave polygon all the vertices are not pointing outwards.

(ii) It is a Simple closed curve and a convex polygon. This is a simple closed curve and as a convex polygon all the vertices are pointing outwards.

(iii) It is Not a curve and hence it is not a polygon.

(iv) It is Not a curve and hence it is not a polygon.

(v) It is a Simple closed curve but not a polygon.

(vi) It is a Simple closed curve but not a polygon.

(vii) It is a Simple closed curve but not a polygon.

(viii) It is a Simple closed curve but not a polygon.

6. How many diagonals does each of the following have?
(i) A convex quadrilateral
(ii) A regular hexagon
(iii) A triangle

Solution:

(i) A convex quadrilateral

For a convex quadrilateral we shall use the formula n(n-3)/2

So, number of diagonals = 4(4-3)/2 = 4/2 = 2

A convex quadrilateral has 2 diagonals.

(ii) A regular hexagon

For a regular hexagon we shall use the formula n(n-3)/2

So, number of diagonals = 6(6-3)/2 = 18/2 = 9

A regular hexagon has 9 diagonals.

(iii) A triangle

For a triangle we shall use the formula n(n-3)/2

So, number of diagonals = 3(3-3)/2 = 0/2 = 0

A triangle has no diagonals.

7. What is a regular polygon? State the name of a regular polygon of
(i) 3 sides
(ii) 4 sides
(iii) 6 sides

Solution:

Regular Polygon: A regular polygon is an enclosed figure. In a regular polygon minimum sides are three.

(i) 3 sides

A regular polygon with 3 sides is known as Equilateral triangle.

(ii) 4 sides

A regular polygon with 4 sides is known as Rhombus.

(iii) 6 sides

A regular polygon with 6 sides is known as Regular hexagon.

All Chapter RD Sharma Solutions For Class 8 Maths

*************************************************

I think you got complete solutions for this chapter. If You have any queries regarding this chapter, please comment on the below section our subject teacher will answer you. We tried our best to give complete solutions so you got good marks in your exam.

If these solutions have helped you, you can also share alarity.in to your friends.