Answer:
Length of smaller square room is 5 m.
Length of bigger square room is 8 m.
Step-by-step explanation:
Sum of area of two squares room =
Let the length of smaller square room be = x meter
Let the length of bigger square room be = x+3 meter
Are of square = 
Area of bigger square room = A =
Area of smaller square room= A'=








x= -8, 5
Rejecting the negative value.
x = 5 m
Length of smaller square room = 5 m
Length of bigger square = (5 + 3 )m= 8 m