Given:
A 7-sides regular polygon.
To find:
The sum of the interior angles of the given regular polygon.
Solution:
The formula for the sum of the interior angles of a regular polygon is:

Where, n is the number of sides of the regular polygon.
The given regular polygon has 7 sides. Putting
in the above formula, we get



Therefore, the sum of the interior angles of the given regular polygon is 900 degrees.