Question

Tick (✓) the correct answer:
Each interior angle of a polygon is 108°. How many sides does it have?
(a) 8
(b) 6
(c) 5
(d) 7

Answer 1

(c) 5
​Each interior angle for a regular n-sided polygon = $180-\left(\frac{360}{n}\right)$

$$\begin{gathered} 180-\left(\frac{360}{n}\right)=108 \\ \Rightarrow \left(\frac{360}{n}\right)=72 \\ \Rightarrow n=\frac{360}{72}=5 \end{gathered}$$