Question 761042
Perimeter = 2*length + 2*width
      17 = 2*length + 2(3.5)
      17 = 2*length + 7
      17 - 7 = 2*length
       10 = 2*length
       10/2 = length
         5 = length.
 Other two sides are 5 cm apiece
Hope this helps.
;-)