Class 7 Maths Chapter 12 Questions and Answers - Free PDF Download
FAQs on NCERT Solutions For Class 7 Maths Chapter 12 Symmetry Exercise 12.1 - 2025-26
1. Where can I find reliable, step-by-step NCERT Solutions for Class 7 Maths Chapter 12, Symmetry, for the 2025-26 session?
You can find detailed and accurate NCERT Solutions for Class 7 Maths Chapter 12 (Symmetry) on Vedantu. These solutions are crafted by subject experts and provide a step-by-step breakdown for every question in all exercises, strictly following the CBSE 2025-26 syllabus and guidelines.
2. What is the correct method to solve questions on identifying lines of symmetry in Exercise 12.1?
The correct method, as demonstrated in the NCERT solutions, is to first draw the given figure. Then, you need to identify all possible lines along which the figure can be folded so that the two halves perfectly overlap. For a regular polygon, the number of lines of symmetry is equal to the number of sides. For example, a square has 4 lines of symmetry.
3. How do the NCERT Solutions for Class 7 Maths Chapter 12 explain the concept of rotational symmetry covered in Exercise 12.2?
The solutions explain rotational symmetry by focusing on three key elements:
- Centre of Rotation: The fixed point around which the figure turns.
- Angle of Rotation: The minimum angle the figure must be turned to look exactly the same as its original position.
- Order of Rotation: The number of times a figure fits onto itself during a full 360° rotation. The solutions provide clear diagrams to illustrate this for each problem.
4. What types of problems are included in NCERT Solutions for Chapter 12, Exercise 12.3?
Exercise 12.3 focuses on identifying shapes that have both line symmetry and rotational symmetry. The solutions guide you on how to check for both properties in a single figure. You will solve problems that require you to name quadrilaterals or other shapes that meet specific criteria for both types of symmetry.
5. Why is it important to follow the step-by-step method from NCERT solutions when finding the order of rotational symmetry?
Following the step-by-step method is crucial for accuracy. It ensures you correctly identify the centre of rotation first, which is the most critical step. Systematically rotating the figure (e.g., by 90°, 120°) helps you count the number of times it aligns with its original position without missing any instance. This methodical approach prevents miscalculation and builds a strong conceptual understanding as per the CBSE pattern.
6. How do NCERT solutions help differentiate between a shape with no symmetry and one with a rotational symmetry of order 1?
The NCERT solutions clarify that these are essentially the same. A shape with a rotational symmetry of order 1 only fits onto itself after a complete 360° turn. This means it has no rotational symmetry in a practical sense. For example, a scalene triangle has an order of rotational symmetry of 1, and the solutions classify it as a shape with no rotational symmetry.
7. How does the solution for a parallelogram's symmetry in Chapter 12 differ from that of a rectangle?
The NCERT solutions clearly distinguish them:
- A parallelogram has no lines of symmetry but possesses rotational symmetry of order 2 about the intersection point of its diagonals.
- A rectangle, on the other hand, has two lines of symmetry (joining the mid-points of opposite sides) and also has rotational symmetry of order 2. This comparison helps clarify that rotational symmetry can exist without line symmetry.
8. According to the method in NCERT solutions, how can you determine if a shape has both line and rotational symmetry?
The correct procedure is to first check for lines of symmetry by drawing and testing mirror-image folds. If a figure has two or more lines of symmetry, the solutions explain that it will automatically have rotational symmetry. The point where these lines intersect becomes the centre of rotation. This rule helps solve problems in Exercise 12.3 efficiently.
9. How do you solve a problem that asks to find the angle of rotation for a regular pentagon?
As per the NCERT solutions, the method is as follows:
1. First, identify the order of rotational symmetry. For a regular pentagon, the order is 5 (equal to its number of sides).
2. The total angle in a full turn is 360°.
3. To find the angle of rotation, divide the total angle by the order of symmetry: 360° / 5 = 72°. Therefore, the angle of rotation is 72°.
















