From the geometric approach the bedroom can be analyzed as a rectangular prism. The volume of the bedroom is the amount of space within it. The formula for calculating volume of a right rectangular prism is: V=L*W*H , where L is the length, W is the width and H is the height. L*W is the floor.
The floor of Catelyn's room is 127 1/2 square feet. L*W=127 1/2
The height of the walls is 8 1/2 feet. H=8 1/2
V=127 1/2 * 8 1/2=127,5*8,5=1083,75 square feet