Parabolic arches are curved structures shaped like a parabola, which is a U-shaped graph. They are commonly used in architecture and engineering because they efficiently distribute weight and can support heavy loads. This design allows for larger spans without the need for additional support, making them ideal for bridges and buildings. One famous example of parabolic arches is the Gateway Arch in St. Louis, which stands as a monument and a functional structure. These arches are not only aesthetically pleasing but also demonstrate the principles of physics and mathematics in real-world applications, showcasing the beauty of geometry in construction.