Page 267 - Math_Genius_V1.0_C6_Flipbook

E:\Working\Focus_Learning\Math_Genius-6\Open_Files\13_Chapter_9\Chapter_9
\ 06-Nov-2024 Bharat Arora Proof-8 Reader’s Sign _______________________ Date __________

Example 13: Find the order of rotational symmetry for each of the following figures:

(a) (b) (c)

Solution: (a) The given figure will look the same when it is rotated at the angles of 60°, 120°, 180°,
240°, 300° and 360°. So, the order of rotational symmetry is 6.
(b) The given figure will look the same when it is rotated at the angles of 180° and 360°.
So, the order of rotational symmetry is 2.
(c) The given figure will look same when it is rotated at the angles of 90°, 180°, 270° and
360°. So, the order of rotational symmetry is 4.
Example 14: Can we have a figure with rotational symmetry
whose smallest angle of symmetry is 13°? Knowledge Desk

Solution: Here, 360  = 27 9 , which is not a whole number. The world’s tallest Ferris wheel
13  13 London Eye has a rotational
Therefore, 13° cannot be the smallest angle of symmetry. symmetry of order 32.

www
MAths connect

The figure given below is the Loksabha chamber of the new parliament building, which was
inaugurated on 28th May 2023. This is a perfect example of symmetry.

The shape of the building has resemblance from the Vijaya temple of Vidisha (MP). The picture of the building
alongwith its outer boundary is shown below.

1. Does the outer boundary of the picture have reflection symmetry? If yes, how many lines of symmetry
are there draw?
2. Does it have rotational symmetry around its centre? If so, find the angles of rotational symmetry.

Practice Time 9C

1. Find the angle(s) of symmetry of the following figures:

(a) (b) (c)

265 Symmetry