Question

Try to draw the geometrical figures for other identities.

(x + y)² ≡ x² + 2xy + y²

Answer 1

Step – 1 : Area of fig. I = x x = x² 

Step – 2 : Area of fig. II = x y = xy 

Step – 3 : Area of fig. III = x y = xy 

Step – 4 : Area of fig. IV = y y = y² 

Area of big square = sum of the areas of figures I, II, III and IV 

∴ (x + y) (x + y) = x² + xy + xy + y² 

(x + y)² = x² + 2xy + y²