Question 577805
Well we know a rectangle has a length (L) and width (W), so the perimeter is just the two lengths plus the 2 widths so:

Perimeter = 2L + 2W = 48 cm

One side (let's use width, W, is 4/5 the length of the other side (L), so:

W= (4/5)*L= 4L/5

Plugging back into our original equation and solving for L (substituting 4L/5 for W):

P = 2L + 2(4L/5) = 48

2L + 8L/5 = 48
10L/5 + 8L/5 = 48
18L/5=48
18L = 48*5
18L = 240   
L= 13 1/3 cm

W= 4L/5 = 4(13 1/3)/5 = 10 2/3 cm

So, Dimensions of rectangle are L x W = 13 1/3 cm x 10 2/3 cm

To check:

P = 2L + 2W = 2(L+W) = 2(13 1/3 + 10 2/3) = 2(24) = 48, ANSWER IS CORRECT