I need help pls my school starts in 45 mins pls I need a answer

Answer:
19 cm
Step-by-step explanation:
Let x be the length
The width would be x+11 since it's 11 cm longer
Perimeter = 2(length+width)
54 = 2(x+x+11)
54 = 2(2x+11)
54 = 4x+22
4x = 32
x = 8
Width = x+11
Width = 8+11
Width = 19