What is the sum of the interior angles of a seven sided polygon?

There is a formula for calculating the sum of the interior angles of a polygon : $${\mathtt{S}} = {\mathtt{180}}{\mathtt{\,\times\,}}\left({\mathtt{n}}{\mathtt{\,-\,}}{\mathtt{2}}\right)$$ where s is the sum and n is the number of angles in the polygon.

Using this formula, find the sum of a 7-sided polygon (septagon):

S = 180 (7-2)

S = 180 * 5

S = 900 degrees.