Question 972565
.
W=width; L=length=3W-60m; A=area
.
{{{A=LW}}} Substitute for L
{{{A=(3W-60)(W)}}}
{{{A=3W^2-60W}}} This is all we can tell about the area 
from the information given.
We do know that W>20m, since if it were less, 
the length would be negative, but that does not tell us any more 
about the area.