1. St. Louis Gateway Arch

2. Looks The base legs are equilateral triangles 60 feet per side Each side at the top is 17 feet wide It is 630 feet tall and 630 feet at the base The view from the top of the arch can reach 30 miles

3. History Arch construction started on February 12, 1963 and lasted to October 28, 1965 A year before construction, a nationwide competition was held to find the best design for the national monument Immediately after it was opened to the public, the unique tram system that combined an elevator cable lift system was installed.

4. Design The architects who designed the Arch was Eero Saarinen and the engineer was Fred Severud Saarinen’s design was chosen after a nationwide competition, held the previous year The Dutch mathematician Christiaan Huygens named this curve

5. Cost It cost about 13 million dollars to build the Arch The transportation system built inside cost about 3.5 million dollars

6. Reliability The structure sways about one inch in a 20 mph wind It is designed to sway up to 18 inches in 150 mile per hour winds. On July 2007, one of the two trams was out of service after a power failure; 200 people were trapped for hours inside

7. Function The Arch commemorates Thomas Jefferson and the westward expansion of the United States It was also built to honor three events in American history; the Louisiana Purchase, the establishment of the Cathedral Basilica of St. Louis, and the Dred Scott case

8. Sources http://www.enchantedlearning.com/history/us/m onuments/stlouisarch/ http://www.enchantedlearning.com/history/us/m onuments/stlouisarch/ http://www.city-data.com/articles/The-Gateway- Arch-in-St-Louis-Missouri.html http://www.city-data.com/articles/The-Gateway- Arch-in-St-Louis-Missouri.html http://www.buzzle.com/articles/gateway-arch- facts.html http://www.buzzle.com/articles/gateway-arch- facts.html http://www.usatoday.com/news/nation/2007-07- 22-st-louis-arch_N.htm