Algebraic Identities – Cut and Rearrange

MathematicsAlgebraAges 13–14

Illustrates (a + b)², (a − b)² and a² − b² using the areas of squares and rectangles. Students drag the handles to change a and b, then press Split/Merge to watch the pieces separate or reassemble: a² − b² is cut into two pieces and rearranged into a (a + b)(a − b) rectangle. The formula with the current numbers updates as the shape changes.