Triangles and Arches in Building Design Gabriel Caluzzi (student), Year 11 Mr. Kneale (teacher), [email protected] University High School, 77 Story St Parkville, VIC 3052 (03) 9347 2022 Fax (03) 9347 2658 Description of Physics This picture shows the use of triangles in a building structure. Triangular shape is almost always used in architecture and building design due to its simplicity, efficiency, and structural value. It is a rigid shape that cannot be changed when pressure is applied, and commonly used to reinforce more yielding shapes such as squares and rectangles. In some situations, a triangular frame can have as much structural strength as a filled formation of the same material. This is commonly seen in the triangular lining of crane arms and building reinforcement, and is used due to the fact that it is much more economical and lightweight. Another key element used in these buildings is arches. Arches are also very strong shapes and are very stable when built with a material good under compression. A force applied to the top of an arch will be carried vertically and horizontally in along the length of the arch's sides all the way to its base, applying a compressive force throughout. Still, very heavy loads can cause an arch to deform, or bend. To overcome this weakness in the picture above, engineers have created an arch covering all 360 degrees. These arches have becomes strong, three-dimensional, symmetrical shapes -- domes. Domes are exceptionally stable structures owing to the fact that they spread their weight out over a full circle.