1959-64 The Marina City Complex | Architect:Bertrand Goldberg | The twin towers cost $36 million to build and were both the tallest residential buildings and the tallest reinforced concrete structures in the world. The complex was built as a city within a city, featuring numerous on-site facilities including a theatre, gym, swimming pool, ice rink, bowling alley, several stores and restaurants, and, of course, a marina. - Via: 1 | 2
A series of Animated GIFs excerpted from Meaning of Pi (1949). The video Explains how pi denotes the ratio of a circle to its diameter, shows the use of circles in art, industry and commerce, outlines a procedure by which the numerical value of pi can be checked and reviewed, and describes the discovery and importance of pi.