Triangular, solid [PLFD]

The shape of the building footprint is approximately triangular in shape, or a tapered wedge shape.

A building with triangular plan shape, Hotel Europe, Vancouver, Canada (Left: S. Brzev; Right: map data ©2013 Google, Province of British Columbia, DigitalGlobe, IMTCAN)

A building with triangular plan shape, San Francisco, California, USA (Map data ©2013 Google, SIO, NOAA, U.S. Navy, NGA, GEBCO, Image Landsat)