The formula for perimeter is:
P = 2 h + 2 w
where P is perimeter = 120 cm, h is height, w is width
we are also given that: h = (2/3) w, therefore:
P = 2 (2/3) w + 2 w = 120
(4/3) w + 2 w = 120
w = 36 cm
Therefore l is:
l = (2/3) w = 24 cm
Hence the dimension should be 24cm by 36 cm
