Part 1) There are a lot of examples. The Colliseum in Rome is an example of an ellipse in architecture. Tires of cars are in a very good approximation a circle. The Arch of triumph is an example of a parabola in the real world, as are many bridges, such as the golden gate bridge. Part 2) The Golden Gate Bridge is a suspension Bridge spanning the Golden Gate, a short strait in San Francisco. It is one of the wonders of the Modern World and it was opened in 1937. It cost around 500 million dollars in today's currency and it is one of the longest suspension bridges in the world and from land to land the distance is 1280 m. The height of the suspensions is 230 m. Part 3) We can think of a parabola of the form y=ax^2 where we need to substitute the values to find a.
