Quadratic equation

 How comes (a²+b²)= a²+b²+2ab ? Prove.

Ans 

We can consider a Square area which is divided into four area inside.Having sides are (a+b)

So as shown in the image

i) Area of the first box which is a square 

Area = a*a

ii) area of the second box which is rectangle

 

Area = l*b

Hence area = b*a

iii) area of the third box which is also a rectangle

 

Area = l*b

Hence area = a*b

iv) Area of the fourth box which is a square 

Area = b*b

So area of the whole square will be

= Area of box first + area of box 2+ area of box 3 + area of box fourth

= a*a + a*b+b*a+b*b

= a²+2ab+b²