Based on the given, the room is a rectangle with Length = 11.5 ft, width = 10.5 ft and height = 10ft. The total wall area can be calculated as the sum of the individual wall areas. The area of opposite walls can be said equal, therefore.
A = A1 + A2
A1 = (11.5 x 10) (2) since two opposite walls
A2 = (10.5 x 10) (2) since two opposite walls
Atotal = 440 sq ft.