Answer:
16 cm
Step-by-step explanation:
Let the width be x
The length will be 3 x since the length is three times the width
Perimeter=2(l+w) where l is length and w is width
By substituting 128 cm for perimeter, x for w and 3 x for l then
128=2(3x+x)
128=8x
[tex]x=\frac {128}{8}=16[/tex]
Therefore, the width is 16 cm, the width is 16*3=48 cm