These NCERT Solutions for Class 7 Maths Chapter 14 Symmetry Ex 14.2 Questions and Answers are prepared by our highly skilled subject experts.

## NCERT Solutions for Class 7 Maths Chapter 14 Symmetry

## Exercise 14.2

Question 1.

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

Answer:

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

Question 2.

Give the order of rotational symmetry for each figure:

Answer:

(a) → 2

(b) → 2

(c) → 3

(d) → 4

(e) → 4

(f) → 5

(g) → 6

(h) → 3

Explanation

Let us mark a point P as show in the figure (i) it requires two rotations each though 180° about the point (x) to come back to its original position.

∴ It has a rotational symmetry of order 2.

Mark a point P as shown in figure (i). It requires two rotations, each through an angle of 180° about the marked point (x) to come back to its original position.

Thus, it has a rotational symmetry of order 2.

(c) Mark a P as shown in figure (i). It requires three rotations each through an angle of 120° about the marked point (x) to come back to its original position.

Thus, it has a rotational symmetry of order 3.

(d) Mark a point P as shown in the figure. It requires four rotations, each through an angle of

900 about the marked point (x) to come back to its original position.

Thus it has a rotational symmetry of order 4.

(e) The figure requires four rotations each of 90°, about the marked point (x) to come back to its original position.

∴ It has a rotational symmetry of order 4.

(f) The figure is a regular pentagon. It requires five rotations, each though an angle of 72° about the marked point to come back to its original position.

∴ It has rotational symmetry of order 5.

(g) The given figure requires six rotations, each though angle of 60°; about the marked point (x) to come back to its original position.

∴ Thus, it has a rotational symmetry of order 6.

(h) The given figure requires three rotations each through an angle of 120°, about the marked point (x) to come back to its original position.

∴ It has a rotational symmetry of order 3.