Using square tiles, students begin the lesson by finding all of the different rectangles that can be made from 12 squares. Students then experiment with pattern blocks to find all of the different ways to use triangles, rhombi, and trapezoids to cover rhombi, trapezoids, and hexagons. Please note that Parts 1, 2, and 3 of It's a Perfect Fit are all included in the same pdf file. ORC cautions that, in Part 3, there is potential for confusion between 3-dimensional objects and 2-dimensional shapes because the figures used to represent 3-dimensional objects look exactly like 2-dimensional shapes, with no indication of the third dimension. In addition to the lesson plan, the site includes ideas for teacher discussion, extensions of the lesson, additional resources, and a discussion of mathematical content. The lesson plan is accompanied by a video illustrating lesson procedures. The user should first locate the It's a Perfect Fit, Part 2 lesson and then access the appropriate video clip. (author/sw)