a rectangle is 3lcm long and l cm wide. if the perimeter of the rectangle is Acm. write down a formula for A
+130511 (1) Perimeter = 2 ( L + W) → P = 2(31 + 1) = 2(32) = 64cm
(2) Area = L * W → A = L * W
So....we can re-arrange (1), thusly :
P = 2(L + W) divide both sides by 2
P/2 = L + W subtract W from both sides
P/2 - W = L
Substituting this into (2), we have
A = [ P/2 - W] * W
So.....substituting the known values for P and W, we have
A = [ 64/2 - 1] * 1 = [ 32 -1] * 1 = 31 cm^2
