To know the minimum rotation we have to do to map the figure onto itself, we just divide 360° by the total number of sides
[tex]\frac{360}{9}=40[/tex]
So, every rotation that can be divide by 40 would be the answer, let's divide
[tex]\begin{gathered} \frac{60}{40}=1.5 \\ \frac{160}{40}=4 \\ \frac{280}{40}=7 \\ \frac{100}{40}=2.5 \end{gathered}[/tex]
Therefore, the right answers are 160° and 280°.
