What is a polygon?• A polygon is a plane figure.• A polygon is a closed region.• A polygon is formed by three or more segments as its sides.• Each side of a polygon intersects only one segment at each of its endpoints.• poli + gonus “many angled”
Parts of a Polygon• sides ▫ consecutive sides included angle ▫ nonconsecutive sides• interior angles / vertex angles ▫ consecutive angles included side ▫ nonconsecutive angles• exterior angles
Parts of a Polygon• Diagonals ▫ A diagonal of a polygon is any segment that joins two nonconsecutive vertices. Figure shows five- sided polygon QRSTU. Segments QS , SU , UR , RT and QT are the diagonals in this polygon.