Final answer:
The Gateway Arch by Eero Saarinen is both 630 feet tall and wide, making it an equilateral arch. Saarinen's design is part of a long history of architectural structures using arches, where the strength comes from the keystone and the precise assembly of voussoirs.
Step-by-step explanation:
The Gateway Arch, designed by Eero Saarinen and completed between 1963 and 1965, stands tall in St. Louis, Missouri. Made of stainless steel, the Gateway Arch is an iconic symbol of the city and measures 630 feet both in height and width. This makes it an equilateral arch, meaning its height and width are exactly the same, creating a balanced and visually striking structure. Saarinen's neo-futuristic style is characterized by large sweeping arching curves, as seen in the Gateway Arch, which serves as a monument to the westward expansion of the United States. An arch's strength comes from its voussoirs and the all-important keystone at the apex. Despite being constructed out of wedge-shaped stones, an arch like the Gateway Arch can bear a great deal of weight thanks to the surrounding supports and the precise way the stones are placed. Saarinen's design for the Gateway Arch fits into a tradition of structures with significant arches, such as those seen in ancient aqueducts and other historical constructions.