octagon50.gif Octagon because it has eight sides. It also has eight vertices or corners. hexagon50.gif Hexagon because it has six sides. It also has six vertices or corners. pentagon50.gif Pentagon because it has five sides. It also has five vertices or corners. square50.gifSquare has four sides. It also has four vertices or corners. tri50.gifTriangle because it has 3 sides. It also has three vertices.