# NCERT Solutions for Class 9 Maths Chapter 11

Free NCERT Solutions for Class 9 Maths Chapter 11 Constructions Exercise 11.1 and Exercise 11.2 in English Medium as well as Hindi Medium updated for new academic session 2020-2021 based on new NCERT Books. Download Prashnavali 11.1 and Prashnavali 11.2 in Hindi Medium to study online or PDF format free for academic session 2020-21. Contents are prepared for all the students of state board and CBSE Board who are using NCERT Books. These NCERT Textbook Solutions 2020-21 are also UP Board Solutions for class 9 Math Chapter 11 and Offline Apps are alos applicable for all the students following NCERT Books 2020-2021 in CBSE Board, UP Board – High School, MP Board – Hindi Medium & English Medium, Gujrat Board and all other boards.

The steps of construction for all the questions are described properly. The method of solutions are simplified for all categories of students.

## NCERT Solutions for Class 9 Maths Chapter 11

 Class: 9 Subject: Maths – गणित Chapter 11: Constructions

### 9th Maths Chapter 11 Solutions in English & Hindi Medium

Class 9 Maths Chapter 11 Constructions Exercise 11.1 and 11.2 Solutions in English and Hindi Medium are given below updated for new academic year 2020-2021. It will help the students of UP Board and MP Board also as these state boards are now using NCERT Textbooks for their board exams. Students can get here the UP Board Solutions for Class 9 Maths Chapter 11 in PDF format.

• ### Study Material for 2020-21

#### Class 9 Maths Exercise 11.1 and 11.2 Solutions in Video

Class 9 Maths Exercise 11.1 Solutions in Video
Class 9 Maths Exercise 11.2 Solutions in Video
##### What are the things generally required for construction?

The following things are generally required 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.

##### What type of Constructions does Class 9 Chapter 11 Contain?

In this chapter, the following constructions using a ruler and a compass:
1. To bisect a given angle. For example: Construct an angle of 45 and hence construct 22 1/2.
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.
3. To construct an angle of 60° etc. For example: Construct an angle of 120 and bisect it.
4. 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.

#### Important Notes on 9th Maths Chapter 11

1. 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.
2. 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.

### Important Questions on 9th Maths Chapter 11

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.            