MATHEMANIA: Polygon

SUM OF OUTER ANGLES OF A POLYGON

Learning Outcomes

• To understand the outer angles of a polygon.

• To understand the relationship between outer and inner angles of a polygon.

• To understand the sum of outer angles of a polygon.

Note

A polygon is a two-dimensional geometric figure that has a finite number of sides. The sides of a polygon are made of straight line segments connected to each other end to end. Thus, the line segments of a polygon are called sides or edges. The point where two line segments meet is called vertex or corners, henceforth an angle is formed. Eg: Triangle, pentagon, hexagon, octagon etc.

If the side of a polygon is extended, the angle formed outside the polygon is called the exterior angle.

In the above figure, angles 1, 2, 3, 4 and 5 are the exterior angles of the polygon. The sum of an interior angle and its corresponding exterior angle is always 180 degrees since they lie on the same straight line.

https://1drv.ms/p/s!Al9YO23A36J-ggvoKdLUPHOsQLGY