The side length of the seating area will be 4 meters less than the side length of the lobby
Given: The side length of the lobby = x and the side length of the seating area = y
If x = 10 (the side length of the lobby) then y = 6 (the side length of the seating area will be 4 meters less than the side length of the lobby ; 10 - 4 = 6)
So answer is A.
The lobby is 10 meters by 10 meters and the seating area is 6 meters by 6 meters