First, find the area of both beds!
For Heidi: 5 x 3 = 15
For Andrew: 5 x (3 x 2) = 30 ft
Added together, the beds have an area of 45 feet. To place soil with a depth of 2 feet, simply multiply by 2. You can think of this as finding the volume of the beds, which is length x width x height, or area x height. The answer is 90 cubic feet!