The angle made with an extension of a side and its corresponding adjacent side
is the exterior angle. Therefore, the sum of the interior angle and the exterior
angle on a vertex is 180°. That is, an interior angle and an exterior angle are
complementary.
Put the pieces of exterior angles of each vertex of the pentagon into the
right circle.
Now, guess the sum of the exterior angles of a pentagon.
Regardless of the number of sides, the sum of the exterior angles of a
polygon is always ( ). |