Question 567874
let the side be x

Area of square = side ^2

area = x^2

width = 2.5

length increases by 5 m

Area including width = (x+5)(x+5)= (x+5)^2

(x+5)^2-x^2=2000

x^2+10x+25-x^2=200

10x=200-25
10x=175
/10
x= 17.5 m