NCERT Solutions for Class 7 Maths Chapter 14 Symmetry Ex 14.2

### NCERT Solutions for Class 7 Maths Chapter 14 Symmetry Ex 14.2

**NCERT Solutions for Class 7 Maths Chapter 14 Symmetry Exercise 14.2**

Ex 14.2 Class 7 Maths Question 1.

Which of the following figures have rotational symmetry of order more than 1?

Solution:

The figure (a), (b), (d), (e) and (f) have rotational symmetry more than 1.

Question 2.

Give the order of rotational symmetry for each figure:

Solution:

Let us take a point S on one end of the given figure. Rotating by 180°, S comes at other end and then again rotating by 180°, it comes at its original position.

∴ Order of rotational symmetry = 360∘/180∘=2

Let us take any point S in figure (1). It takes two rotations to come back to its original position.

∴ Order of rotational symmetry = 360∘/180∘=2

Let us mark any vertex of the given figure. It takes three rotations to come back to its original shape.

∴ Order of rotational symmetry = 360∘/120∘=3

Order of rotational symmetry = 360∘/90∘=4

∴ Order of rotational symmetry = 360∘/90∘=4

(f) The given figure is a regular pentagon which can take one rotation at an angle of 72°.

∴ Order of rotational symmetry = 360∘/72∘=5

(g) The given figure requires six rotations each through an angle of 60°

∴ Order of rotational symmetry = 360∘/60∘=6

(h) The given figure requires three rotations, each through an angle of 120°.

∴ Order of rotational symmetry = 360∘/120∘=3