Question

Which of the following figures have rotational symmetry as order 1:

• A. Figure (a)
• B. Figure (b)
• C. Figure (c)
• D. Figure (d)

Answer 1

The correct option is C Figure (c)

Figures (a) and (f) will look the same if rotated by 90${}^o$, 180${}^o$, 270${}^o$ or 360${}^o$. Hence, they have an order of 4.

Figures (b) and (e) will look the same if rotated by 120${}^o$, 240${}^o$ or 360${}^o$. Their order of rotational symmetry will thus be 3.

If we rotate figure (d) by 180${}^o$ or 360${}^o$, we will get the same figure. Hence, it has an order of 2.

But option (c) has an order of only 1 since the same figure can be obtained if the figure is rotated by 360${}^o$.

Therefore, the rotational symmetry of order more than 1 are (a),(b),(d),(e) and (f) because in these figures, a complete turn, more than 1 number of times, an object looks exactly the same.