To find the number of sides (\( n \)) in a polygon given the sum of its interior angles (\( s \)), you can use the formula:
\[ s = 180(n - 2) \]
Given that \( s = 1260^\circ \), we can set up the equation:
\[ 1260 = 180(n - 2) \]
Now, divide both sides by 180 to solve for \( n - 2 \):
\[ \frac{1260}{180} = n - 2 \]
Calculating the left side:
\[ 7 = n - 2 \]
Now, add 2 to both sides:
\[ n = 7 + 2 \] \[ n = 9 \]
Thus, the polygon has 9 sides.
So, the answer is 9 sides.