Let width=x m
so length=3x-7
Since area =66m^2
L×B=66
(3x-7)×x=66
3x^2-7x=66
3x^2-7x-66=0
3x^2-(18-11)x-66=0
3x^2-18x+11x-66=0
3x(x-6)+11(x-6)=0
So (x-6)(3x-6)=0
So x=2 and x=6
If x=2
Width=2
Length=2×3-7=-1
So this value of x does not exist because length cannot be negative
So x=6m
Width=6m
length=3×6-7=11m