This video is one of a series (all 5 minutes and under) which align to the 5th Grade Common Core Math Standards. This particular video relates to 5.G.3 "Understand that attributes belonging to a category of two-dimensional figures also belong to all subcategories of that category."
You can download this video and include it in your own blogs or class website. It is a useful tool for 'virtual teaching' to students at home, or educating parents in a dignified way, or using directly in your classroom with your kids.
Technical Note: This video is a (.swf) Flash file. It may be opened directly on most computers. An alternate method for opening the file is to right-click on your downloaded file, and choose 'Open With...' and select Windows Media Player.