# NCERT Exemplar Class 7 Maths Chapter 12 Solutions: Practical Geometry Symmetry and Visualising Solid Shapes

NCERT Exemplar Class 7 Maths Solutions Chapter 12 ‘Practical Geometry Symmetry and Visualising Solid Shapes’ is a collection of a diverse variety of exercise solutions to help you with the concepts. The concepts covered in this chapter are of practical importance as it is evident from the name of the chapter of NCERT Exemplar Class 7 Maths. In this chapter, you will learn how to construct two parallel lines intersected by a given transversal, and different triangles along with the essential conditions required for their construction. You will also learn about line and rotational symmetry in this chapter. Lastly, you will be amazed to know about solid shapes and their oblique and isometric representations.

There are a total of 124 questions in the exercise of this chapter. These questions are arranged in an orderly fashion of increasing difficulty level to make you proficient in these concepts by the end of the chapter. The questions require general aptitude and are fun to solve. It is recommended that you solve these exercises before you appear in your CBSE school exam to score full marks.

You will find the answers to the exemplar questions very precise and 100% accurate. The maths faculty of Instasolv keep themselves updated with the latest exam patterns of CBSE and board guidelines to assist you in writing answers which comply with the demand of the question. You will see significant improvement in not only your marks in maths but a boost in your overall rank as it will raise the bar of your performance in exams.

## Important Topics Covered in NCERT Exemplar Class 7 Maths Solutions Chapter 12

**Introduction to Construction of Parallel Lines**

You can draw a parallel line passing through a given point P which lies outside the line given in the question as l with the help of the properties of a transversal passing through two parallel lines such as equal corresponding angles and alternate interior angles or supplementary interior angles lying on the same side of the transversal.

**Construction of a Triangle**

To construct a triangle, we must know at least three of its dimensions. The three dimensions given can be of any of the following cases:

- When three sides of the triangle are given (SSS)
- When two sides and the angle included between them are given (SAS)
- When any two angles and one side of the triangle are given (AAS or ASA)
- When hypotenuse and one of the remaining sides of a right-angled triangle are given (RHS)

**Line Symmetry**

If we fold a given figure on a line and the two sides of the figure happen to coincide over one another, the figure is said to exhibit line symmetry.

There are many lines of symmetry in the regular polygons because there are many equal sides and equal angles in a regular polygon. The lines of symmetry in a regular polygon are equal to the number of sides of the polygon.

Mirror forming laterally inverted images is another example of line symmetry.

**Rotational Symmetry**

This occurs when a figure is rotated by 360°, the number of times the figure coincides with its original position gives the rotational symmetry exhibited by an object.

**Solids:**

Two types of sketches can be used to represent solid objects:

- Oblique sketches
- Isometric sketches.

## Exercise Discussion of NCERT Exemplar Class 7 Maths Solutions Chapter 12

- In the first 28 questions, you will be required to select the correct answer from a multiple-choice question each.
- In the exercise solutions from question no. 29 to 58, you will be filling the blanks. This will help you get sorted about the concepts completely.
- Up to question no 92, you will need to check if the given statements are true or false.
- In the latter part of the NCERT Exemplar chapter, you will be required to answer detailed subjective questions, also you might have to sketch the oblique or isometric view of different objects.
- To solve the questions from 114 to 124, you will require in-depth knowledge about the lines and concepts of symmetry.

## Why Use NCERT Exemplar Class 7 Maths Solutions Chapter 12 by Instasolv

- The NCERT Exemplar Class 7 maths chapter 12 prepared by the expert team of Instasolv are based on research. It will help you clear your queries at just one place without having to hustle here and there.
- The questions in this chapter are interesting yet a little tricky. This is why we have answered them all step by step for you. Refer to them whenever you want and prepare the chapter easily. Our online platform is very inclusive and user friendly.