Rectangle (walls)
48 sq units
8 × 6
Roof (triangle)
12 sq units
½ × 8 × 3
Total area
60 sq units
48 + 12 = 60
Total = (width × wall height) + (½ × width × roof height)
Drag the three dots: the side dot sets the width, the lower dot sets the wall height, and the top dot sets the roof peak. The total area is just the walls plus the roof.