Question 751035
let length is L 
width is B
L= 7/2 B 
P =2(L+B)
as per condition 
90= 2(7/2B+B)
90=9/2 B
B = 90x2/9 =20m
length =7/2 of 20 =70m

ANSWER  
L=70m
B=20m