# NCERT Solutions for Class 9 Maths Chapter 11

Free Download NCERT Solutions for Class 9 Maths Chapter 11 Constructions Exercise 11.1 and Exercise 11.2 and प्रश्नावली 11.1 और प्रश्नावली 11.2 की रचनाएँ to study online of in PDF form to download free. These NCERT Solutions and Offline Apps are applicable for all the students following NCERT Books in CBSE Board, UP Board – High School, MP Board – Hindi Medium & English Medium, Gujrat Board and all other boards.

 Class 9: Maths – गणित Chapter 11: Constructions

## NCERT Solutions for Class 9 Maths Chapter 11

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### 9 Maths Exercise 11.1 Solutions

Class 9 Maths Chapter 11 Constructions Exercise 11.1 Solutions in English. Click here to see Exercise 11.2 or go for प्रश्नावली 11.1 और प्रश्नावली 11.2 in Hindi or go back to Class 9 Maths main page. Move to Top of the page.

### 9 Maths Exercise 11.2 Solutions

Class 9 Maths Chapter 11 Constructions Exercise 11.2 Solutions in English. Click here to see Exercise 11.1 or go for प्रश्नावली 11.1 और प्रश्नावली 11.2 in Hindi or go back to Class 9 Maths main page. Move to Top of the page.

### 9 गणित के प्रश्नावली 11.1 के हल

Class 9 Maths Chapter 11 Constructions Exercise 11.1 Solutions in Hindi. Click here to see प्रश्नावली 11.2 or go for Exercise 11.1 and Exercise 11.2 in English or go back to Class 9 Maths main page. Move to Top of the page.

### 9 गणित के प्रश्नावली 11.2 के हल

Class 9 Maths Chapter 11 Constructions Exercise 11.2 Solutions in Hindi. Click here to see प्रश्नावली 11.1 or go for Exercise 11.1 and Exercise 11.2 in English or go back to Class 9 Maths main page. Move to Top of the page.

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##### Important Terms with Examples on Constructions
• You must need the following things for construction
• (i) A graduated scale, on one side of which centimetres and millimetres are marked off and on the other side inches and their parts are marked off.
• (ii) A pair of set – squares, one with angles 90°, 60° and 30° and other with angles 90°, 45° and 45°.
• (iii) A pair of dividers (or a divider) with adjustments.
• (iv) A pair of compasses (or a compass) with provision of fitting a pencil at one end.
• (v) A protractor.
• In this chapter, you will do the following constructions using a ruler and a compass:
• To bisect a given angle. For example: Construct an angle of 45 and hence construct 22 1/2.
• To draw the perpendicular bisector of a given line segment. For example: Draw a line segment 6.4 cm and construct its perpendicular bisector.
• To construct an angle of 60° etc. For example: Construct an angle of 120 and bisect it.
• To construct a triangle given its base, a base angle and the sum of the other two sides. For example: Construct a right angled triangle whose hypotenuse measure 5.3 cm and the length of one of whose sides containing the right angle measures 4.5 cm.
• To construct a triangle given its base, a base angle and the difference of the other two sides. For example: Construct a triangle ABC, in which BC = 5.2 cm and angle B = 30 and the difference of the other two sides is 3.5 cm.
• To construct a triangle given its perimeter and its two base angles. For example: Construct a triangle, if the perimeter is 10.4 cm and the two base angles are 45 and 120.

#### What should we have for constructing a geometrical figure?

(i) A graduated scale, on one side of which centimetres and millimetres are marked off and on the other side inches and their parts are marked off.
(ii) A pair of set – squares, one with angles 90°, 60° and 30° and other with angles 90°, 45° and 45°.
(iii) A pair of dividers (or a divider) with adjustments.
(iv) A pair of compasses (or a compass) with provision of fitting a pencil at one end.
(v) A protractor.

#### What is geometrical construction?

A geometrical construction is the process of drawing a geometrical figure using only two instruments – an ungraduated ruler, also called a straight edge and a compass.

#### What are the topics to learn in Class 9 constructions?

The following topics to learn in class 9 constructions:
1. To bisect a given angle.
2. To draw the perpendicular bisector of a given line segment.
3. To construct an angle of 60° etc.
4. To construct a triangle given its base, a base angle and the sum of the other two sides.
5. To construct a triangle given its base, a base angle and the difference of the other two sides.
6. To construct a triangle given its perimeter and its two base angles.

#### What are the different type of triangles to make in class 9?

The following three situations are to be done in class 9 constructions:
1. When base angles are given and some of all sides are given.
2. When base angle is given and some of two sides are given.
3. When base angle is given and different of two sides are given.

#### How to make the CONSTRUCTIONS chapter easy?

Only practice more and more to make this chapter easier.