This is a lesson I usually start off with when we study polygons, triangles and quadrilaterals. I usually pair students up and each gets a computer or Ipod to research all of these topics on the site, www.amathsdictionary.com. The students can then used this sheet for reference as we work our way through this material.
Researching topics on all polygons up to decagon, irregular and regular polygons, quadrilaterals and different types of triangles.
This lesson was made for 5th grade math but would be suitable for 4th or 6th as well.