Question:
Tick (✓) the correct answer:
Each interior angle of a polygon is 135°. How many sides does it have?
(a) 8
(b) 7
(c) 6
(d) 10
Solution:
(a) 8
Each interior angle of a regular polygon with $\mathrm{n}$ sides $=180-\left(\frac{360}{n}\right)$
$\Rightarrow 180-\left(\frac{360}{n}\right)=135$
$\Rightarrow \frac{360}{n}=45$
$\Rightarrow n=8$