Changes

# As with the one-sided polygon, there is no such thing as a two-sided polygon.  (This would be two overlapping [[line segment]]s.)

# As with the one-sided polygon, there is no such thing as a two-sided polygon.  (This would be two overlapping [[line segment]]s.)

# [[Triangle]] - see [[isosceles triangle]], [[equilateral triangle]], [[right triangle]]

# [[Triangle]] - see [[isosceles triangle]], [[equilateral triangle]], [[right triangle]]

# [[Square]] - a [[rectangle]] whose sides are all the same length

# [[Quadrilateral]]:  See also [[square]] and [[rectangle]]

# [[pentagon (geometry)|Pentagon]]

# [[pentagon (geometry)|Pentagon]]

# [[Hexagon]] - the shape of a bee hive cell, also used in some board games

# [[Hexagon]] - the shape of a bee hive cell, also used in some board games