Answer:
84.5 square yards roof
area of a square is A = a²
a = length of each side
The 2 triangular faces do not constitute "roof". The roof only covers 2 of the 3 square surfaces. Since we know the length of all edges is 6.5 yards:
A = (6.5)²
A = 42.25 yd²
This gives us the area of 1 of the 3 square sides. Since the roof covers 2 of the 3 sides (one is the floor/base), we must multiply times 2.
42.25 x 2 = 84.5
The height of the house would give you the area of the triangular faces, but since they are not considered "roof", you do not need to calculate their area.