Problem 4: (5 points) The flat roof of the steel-frame building shown below is intended to support a total dead load of 2 k/ft² over its surface. Given that AB CD=4ft and AD = BC= 5ft. THE a) Sketch the tributary loading along each edge beam. (2 points) b) Determine the roof load within region ABCD that is transmitted to beam BC. (3 points) A B D C