It may be necessary for students to consider the area of some shapes in relation to the entire square. For instance, how many red triangles in the diagram below can be placed on the square so that there are no overlaps or gaps? Once a student has determined that it is possible to place 16 red triangles on the square, then the area of the red triangle is 1/16 unit2. The other small triangles are also 1/16 unit2. Further, the larger 45 45 90 triangles are equal in size to two red triangles, and the trapezoids are equal to three red triangles.