Answer:
To know how many sides has this polygon, knowing the sum of their interior angles, we can use this expression:
b = (n-2) * 180
Where b is the sum of the interior numbers and n the number of sides.
Knowing this, we can replace, as we kno w it
b = (n-2)) * 180
1980 = (n-2)*180
We can know solve the equation
We can use this distributive property to operate the parenthesis, which says that if we find this expression a(b+c), we can operate doing ab+ac, and, if we substract, we can also use it, as a(b-c) = ab-ac
1980 = (n-2)*180
1980 = 180n - 180*2 = 180n - 360
1980 = 180n - 360
1980 + 360 = 180n
[tex]\frac{1980+360}{180} = n.[/tex]
13 = n
So we know the polygon will have 13 sides..
