Page 235 - Start Up Mathematics_7

(e) (f)

2. Give the order of rotational symmetry for each figure:

(a) (b) (c) (d)

3. If a figure has two or more lines of symmetry, should it have rotational symmetry of order
more than 1?
4. Name the quadrilaterals which have both line and rotational symmetry of order more than 1.
5. After rotating by 60° about a centre, a figure looks exactly the same as its original position.
At what other angles will this happen for the figure?

Exemplar Problems

1. The order of rotational symmetry in the given figure is:
(a) 4 (b) 8
(c) 6 (d) infinitely many

2. Which of the following letters of English alphabets have more than 2 lines of symmetry?

(a) Z (b) O (c) E (d) H
3. Which of the following are reflections of each other?

(a) (b) (c) (d)

4. __________ triangle is a figure that has a line of symmetry but lacks rotational symmetry.
5. Order of rotational symmetry of a semicircle is two. (True/False)
6. An equilateral triangle has six lines of symmetry. (True/False)

7. In each of the following figures, write the number of lines of symmetry and order of rotational
symmetry.

(a) (b) (c) (d)

8. Does the given figure have rotational symmetry?

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