Question 121968
Let L=length and W=width

then L=W+1 

and using pitagoras theorem L^2+W^2=4^2

then  (W+1)^2+W^2=16
then   2W^2+2W-15=0

so W= (-2+sqrt(124))/4 or W=(-2-sqrt(124))/4 the second solution is negative so
W= (-2+sqrt(124))/4 using L=W+1 you can calculate L