Question

How many sides does a polygon have if the sum of its interior angles is 30 right angles ?

• A. $15$
• B. $17$
• C. $19$
• D. $20$

Answer 1

The correct option is B $17$

Let the number of sides of the polygon be $n$

Sum of the interior angles of a polygon of $n$ sides is ${180}^0(n-2)$
Given, sum of interior angles $=30\times {90}^o$
So, $30\times {90}^o={180}^0(n-2)$
$15=n-2$
$=>n=17$