Each polygon will always divide into two triangles fewer than the number of its sides. A hexagon will have four triangles. An octagon will have six triangles. So the sum of the interior angles of ...

The sum of interior angles is \((6 - 2) \times 180 = 720^\circ\). One interior angle is \(720 \div 6 = 120^\circ\). If the side of a polygon is extended, the angle formed outside the polygon is ...

Two-dimensional (2D) shapes are completely flat. They have two dimensions – length and width. A polygon is a closed 2D shape with straight sides that meet at vertices. Polygons can be regular or ...