Verification of algebraic identities geometrically?

Question

(x+a)(x=b)=x2 +(a+b)x+ab.

Answer 1

draw a rectangle, sides x+a and side x+b

draw appropriate lines at each x mark (horizontally, and vertically), creating sub rectangels x^2, ax, bx, ab

Notice that the sum of the areas add to (x+a)(x+b)