More Factoring with Algebra Tiles x^2 + 4x + 4

These algebra tiles form a square..hence the algebra that the tiles represent is a perfect square.
Look at each side of the square and you will see a length of x and then two little yellow squares making each side x + 2.
(x + 2)(x + 2) when FOILed is x^2 + 2x + 2x + 4 which when combining like terms becomes x^2 + 4x + 4.  If you look at the algebra tiles, there is the large blue square that represents x^2, four long green rectangles that are each x making 4x and 4 small yellow squares that represent 4.
see the post: http://mathconfidence.blogspot.com/2013/06/learning-factoring-with-algebra-tiles.html for more info and links on factoring polynomials with algebra tiles!