Adjust the pentagon below by dragging any orange dot. By clicking on the top left command line,
you can switch it between a
Properties of regular pentagons
Like any regular polygon, to find the interior angle we use the formula
(180n–360)/n . For a pentagon, n=5.
See Interior Angles of a Polygon
To find the exterior angle of a regular pentagon, we use the fact that the exterior angle
forms a linear pair
with the interior angle, so in general it is given by the formula
See Exterior Angles of a Polygon
On the right is the well-known headquarters building for the US Department of Defense -
commonly known as "The Pentagon" due to its shape.
As you can see, it has several rings of offices inside.
These, in geometric terms, would be called concentric regular pentagons, since they share a common center point
and are symmetrical the way a regular polygon is.
It was built in 1943, has 17.5 miles (28 Km) of corridors,
and a floor area of 6,500,000 square feet (604,000 m2).
In 1992, the Pentagon became a National Historic Landmark.