Answer:
The number of sides is 7
Step-by-step explanation:
Once the sum of interior angles is equal to 900º and the sum of interior angles is given by
[tex]S=(n-2) \cdot 180\º, \text{ as }n \text{ being the number of sides}[/tex]
[tex]900\º = (n-2) \cdot 180\º[/tex]
[tex]\dfrac{900\º}{180\º} = (n-2)[/tex]
[tex]5 = (n-2)[/tex]
[tex]5+2 = n-2+2[/tex]
[tex]\boxed{n=7}[/tex]