Question

Find the number of sides in a regular polygon if each exterior angle is ${72}^{\circ }$.

• A. $3$
• B. $5$
• C. $7$
• D. $10$

Answer 1

The correct option is B $5$

$\text{Each exterior angle of regular polygon of n sides is given by}{\frac{360}{n}}^o$
$\text{According to question}$
${\frac{360}{n}}^o={72}^o$
$\Rightarrow n=\frac{360}{72},n=5$

$\therefore \text{Number of sides =5}$