Answer:
5 cm by 4 cm
Explanation
A = L x W 20 = L x W
P = 2L + 2W (18 = 2L + 2W)/2
9 = L + W W = 9 - L
20 = L (9 - L) 20 = 9L - L^2
L^2 - 9L + 20 = 0 (L - 4)(L - 5) = 0
L = 4 L = 5
The longer one is the length, so L = 5, and W = 4.
5.3m questions
6.9m answers