Question

The sum of the measures of the angles of regular polygen is ${2160}^{\circ }$. How many sides does it have ?

• A. $16$
• B. $18$
• C. $14$
• D. $12$

Answer 1

The correct option is C $14$

Sum of all angles in a $n$ sided polygon are$={90}^{\circ }(2n-4)$
$\Rightarrow 2160=90(2n-4)$
$2n=24+4$
$\therefore n=14$
Hence the polygon has 14 sides.