NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.2 (Rationalised Contents)
NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.2 are the part of NCERT Solutions for Class 7 Maths (Rationalised Contents). Here you can find the NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.2.
- NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.1
- NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.2
- NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.3
Ex 12.2 Class 7 Maths Question 1.
Which of the following figures have rotational symmetry of order more than 1?
Solution:
The figures (a), (b), (d), (e) and (f) have rotational symmetry of order more than 1.
Ex 12.2 Class 7 Maths Question 2.
Give the order of rotational symmetry for each figure:
Solution:
(a) Let us mark a point S on one end of the given figure. By rotating the figure 180°, S comes at other end and then again by rotating the figure 180°, it comes at its original position.
(b) Let us mark a point S on one end of the given figure. By rotating the figure 180°, S comes at other end and then again by rotating the figure 180°, S comes at its original position.
(c) Let us mark any vertex of the given figure as P. It takes three rotations of 120° to come back to its original position.
(d) Order of rotational symmetry = 360°/90° = 4
(e) Order of rotational symmetry = 360°/90° = 4
(f) The given figure is a regular pentagon which can take one rotation of 72° to obtain its original position.
∴ Order of rotational symmetry = 360°/72° = 5
(g) The given figure requires six rotations of 60° to obtain its original position.
∴ Order of rotational symmetry = 360°/60° = 6
(h) The given figure requires three rotations of 120° to obtain its original position.
∴ Order of rotational symmetry = 360°/120° = 3
Related Links:
NCERT Solutions for Maths Class 8
NCERT Solutions for Maths Class 9
NCERT Solutions for Maths Class 10
NCERT Solutions for Maths Class 11