angles and grids
[Photo ©2010, Chicago, Illinois, USA]
The interesting thing about the heavy use of glass in architecture is how it enables the building to be in constant change. Sure, literally on a surface level, but it will change from day-to-day with the differing reflections and light. Also, the buildings influence the changes in their neighbors as well, interactive.
L – R, IBM Building, Trump International Hotel and Tower.
(Larger photo, 2x, available here https://williamboschdotcom.files.wordpress.com/2010/12/ibmtrump1000.jpg)