A square piece of tin of side length 20 cm has four squares of side length x cm removed from each corner. the sides are folded up to form a tray. the centre square forms the tray base a write an expression for the side length of the base of the tray. b write an expression for the area of the base of the tray. expand your answer. c find the area of the tray base if x = 3. d find the volume of the tray if x = 3
