Calculate the area and perimeter of a regular octagon using its side length. A regular octagon is an eight-sided polygon with all sides of equal length and all interior angles equal to 135 degrees.
For a regular octagon with side length s:
A regular octagon is a polygon with eight equal sides and eight equal angles. Each interior angle measures 135 degrees, and the sum of all interior angles is 1080 degrees. Regular octagons are commonly seen in architecture, design, and as the shape of stop signs in many countries.