Question

Find the number of sides of a polygon whose sum of interior angles is $900°$.

Answer 1

Sum of all interior angles of $n$ sided polygon is $(n-2)\times 180°$

We have a polygon whose sum of interior angles is $900°$

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

So,

$$\begin{gathered} \left(n-2\right)\times {180}^{\circ }={900}^{\circ } \\ \Rightarrow \left(n-2\right)=\frac{{900}^{\circ }}{{180}^{\circ }}=5 \\ \Rightarrow n=5+2=7 \end{gathered}$$

Hence , the required number of sides in a parallelogram is $7$

Thus, the parallelogram is Heptagon