The order of rotational symmetry in the figure 12.16 given below is
(a) 4
(b) 2
(c) 1
(d) Infinitely many

Solution:

We know that

Number of times a figure fits onto itself in one full turn is known as the order of rotational symmetry.

The figure has a rotational symmetry of order 2.

Therefore, the order of rotational symmetry is 2.

✦ Try This: Show the rotational symmetry of an equilateral triangle.

An equilateral triangle has 3 sides of equal measure and each internal angle measuring 60° each.

From the figure, the equilateral triangle fits 3 times at every 120 degree angle.

The order of rotational symmetry is 3 and the angle of rotation is 120 degrees.

Therefore, the rotational symmetry of an equilateral triangle is shown above.

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 14

NCERT Exemplar Class 7 Maths Chapter 12 Problem 6

The order of rotational symmetry in the figure 12.16 given below is: (a) 4, (b) 2, (c) 1, (d) Infinitely many

Summary:

The order of rotational symmetry in the figure 12.16 given below is 2.

☛ Related Questions:

• The name of the given solid in Fig 12.17 is: (a) triangular pyramid, (b) rectangular pyramid, (c) re . . . .
• The name of the solid in Fig. 12.18 is: (a) triangular pyramid, (b) rectangular prism, (c) triangula . . . .
• All faces of a pyramid are always: (a) Triangular, (b) Rectangular, (c) Congruent, (d) None of these