Answer:
9cm
Step-by-step explanation:
A rectangle has two sets of two equal sides. Using this, you can double 35 to get 70 and that is the sum of 2 sides.
Since the entire perimeter is 88, that leaves the rest of the total to be 18.
If you divide 18 by 2 (since there are 2 sides), you get 9. That is the width! Hope this helps.