A ploygon is a flat 2-D shape that is enclosed by straight lines. A 2-D shape is a flat shape that has the two dimensions of length and width. A polygon can be Regular (all sides are equal) or Irregular (all sides are not equal). A polygon can be concave or convex. We will learn more about how to identify these when we learn about angles. For now try to observe the shape to notice the difference. A Quadrilateral is a polygon with 4 sides. For example: square, rhombus, rectangle, trapezoid, and parallelogram. Let us learn more: http://www.learnalberta.ca/content/me3usa/flash/index.html?goLesson=14 Sorting Quadrilaterals: http://www.crickweb.co.uk/ks2numeracy-shape-and-weight.html#quad http://www.sheppardsoftware.com/mathgames/earlymath/shapes_shoot.htm https://www.mathgames.com/geometry 3D Shapes https://www.learner.org/interactives/geometry/3d_prisms.html?fbclid=IwAR2fjsK68o_IdW55nZ-fZPdtQ8EEvP19uSA8CX5iH14CEAFbxoK4QI2SetI