suppose that p>q>0. sketch a square of side p and another square of side q and give a pictorial demonstration of the identity p^2-q^2=(p+q)(p-q)
Let p = 5 = the side of the larger square Let q = 3 = side of smaller square
So
p^2 - q^2 = 5^2 -3^2 = 16 = the number of small squares between the two squares
And p^2 - q^2 = (p + q) ( p -q) = (5 + 3) (5 -2) = (8) (2) = 16
+39 
