Question

The sum of angles of a polygon is ${1440}^{\circ }$. Find the number of sides of the polygon.

• A. 8 sides
• B. 12 sides
• C. 7 sides
• D. 10 sides

Answer 1

The correct option is D 10 sides

Sum of all the angles of the given polygon = ${1440}^{\circ }$

Sum of all the angles of $n$ sided polygon
= $(n-2)\times {180}^{\circ }$
Given, sum of all angles = 1440${}^{\circ }$
$\therefore {1440}^{\circ }=(n-2)\times {180}^{\circ }(n-2)=\frac{{1440}^{\circ }}{{180}^{\circ }}=8n-2=8n=10$

Therefore, the number of sides of the given polygon is 10.