Question

find the measure of a single exterior angle of a regular nonagon. if necessary, round to the nearest tenth.

Explanation:

Step1: 多边形外角和定理

任意多边形的外角和都为\(360^{\circ}\)。

Step2: 计算正九边形单个外角的度数

正九边形有\(9\)个外角，且这\(9\)个外角都相等，所以单个外角的度数为\(\frac{360^{\circ}}{9}\)。

$$ \frac{360^{\circ}}{9} = 40^{\circ} $$

Answer:

\(40^{\circ}\)