Answer:
width=10cm
length=25cm
Step-by-step explanation:
let the width be x
then the length is 3x - 5
the perimeter is 2 widths and 2 lengths so
2x+2(3x-5)=70
solve the equation
2x + 6x - 10=70
8x=80
x=10
length=3x-5
= 30-5
=25
