Answer:
length: 45cm
width: 33cm
Step-by-step explanation:
formula for perimeter is: 2x+2y= p
p in this case is 156 cm
let's call x the length and y the width. it says that the width is 12 cm less than the length so
y=x-12
so using substitution:
2x+2(x-12)=156cm
2x+2x-24=156cm
4x-24=156cm
4x= 180cm
x= 45cm -> length
x-12= 33cm ->width