Closed figure with more than three sides

A polygon is a closed figure with 4 equal sides

You can also break the word down for her. Poly: Meaning many, gon : Meaning side. Together many sides. Anything other than a straight line or an angle (two lines connected) is a polygon. I.e. Triangle, square, rectangle, octagon....

If I make it simplest then a polygon is a two-dimensional or plane figure surrounded by a closed path. The closed path is made up of straight line segments. A polygon can be classified on the following major areas:

1) Number of sides

2) convexity

3) symmetry

For a general idea you can tell your daughter that polygon or a simple shape is classified according to its number of sides. For example: Monogon, digon, triangle, quadrilateral, pentagon, hexagon, heptagon, nonagon and decagon have one to 10 numbers of sides increasingly respectively. For more details you can go to en.wikipedia.org

1) Number of sides

2) convexity

3) symmetry

For a general idea you can tell your daughter that polygon or a simple shape is classified according to its number of sides. For example: Monogon, digon, triangle, quadrilateral, pentagon, hexagon, heptagon, nonagon and decagon have one to 10 numbers of sides increasingly respectively. For more details you can go to en.wikipedia.org