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