Answer: The correct option is (A) 18°.
Step-by-step explanation: We are given to find the degree of rotation for a regular 20-sided polygon.
We know that
if a regular polygon has n sides, then its degree of rotation is given by
![d=(360^\circ)/(n).](https://img.qammunity.org/2019/formulas/mathematics/high-school/9fl8cixtb7qzowqgeulj6vn1s7p5e36ona.png)
For the given regular polygon, we have
n = 20.
Therefore, the degree of rotation of the given polygon is given by
![d=(360^\circ)/(20)=18^\circ.](https://img.qammunity.org/2019/formulas/mathematics/high-school/su5lnf10ipfck7buanyafjkobadk1ntmel.png)
Thus, the required degree of rotation is 18°.
Option (A) is CORRECT.