Question

How many sides does a polygon have whose sum of the interior angles is ${1980}^o$?

• A. $10$
• B. $13$
• C. $11$
• D. None of these

Answer 1

The correct option is B $13$

Sum of the interior angles of a polygon of $n$ sides is ${180}^0(n-2)$
Given, sum of whose interior angles is ${1980}^o$
$=>{180}^0(n-2)={1980}^o$
$=>n-2=11$
$=>n=13$
Hence, the polygon has $13$ sides.