This activity is used to provide the students with practice multiplying binomials as well as factoring trinomials. It is a Microsoft PowerPoint presentation that has 5 different versions, so you can use it over and over without the students catching on.
 Simply print one version at a time onto 4 to 8 different color pieces of paper. [1a] If you can have the sheets laminated, it will increase the durability of the triangle pieces.  Cut out the triangles (of have a student cut them out - they love to do that kind of thing).  Take all the pieces and place them in a small envelopes, one envelope per color.
 Divide the students into small groups (heterogeneous is always best).  Give each group an envelope and have them use their brains / notes / book to pieces the triangles together.  When all the groups are done, you can display the original PowerPoint slide that corresponds to the version you are using. Have the students check their work.
 Most importantly, have the students write down their decision making processes: did they use variables to determine a match (type, quantity or combination); did they use sign order; did they multiply the binomials and match; did they compare middle terms of the trinomials; or, did they just know (intuition is valuable, but make them pick a method that makes sense).
There is also a slide has some blank triangles. If you choose, have students create their own to challenge each other.