These cards can be laminated, cut apart, and used in a variety of ways to reinforce finding the measures of area and perimeter. I have used these cards as a type of “I Spy” by hanging them around the room as students walk around and determine the perimeter and area. This has also worked well as an extension activity for early finishers. For whole group additional practice I placed a set of cards at each table and we rotated every couple of minutes. This would also work well as a center activity! How you use them is up to you!