geometrical verification of algebric identity (a+b)²=a²+2ab+b²

Answer 1

Draw a square of side a+b.
Draw lines parallel to the sides of the square at the junction of a and b to make four rectangles of areas a², ab, ba and b².
Calculate the area of the big square in two ways:
1. side=(a+b)
2. sum of four rectangles enumerated above.