An office building is built in the shape of a four-sided pyramid. It stands 740 feet tall and is 160 feet wide at its base. Imagine that a coordinate grid is placed over a side of the building. In the coordinate grid, each unit represents one foot. Enter an absolute value function whose graph is the V-shaped outline of the sides of the building. Take one corner of the building to be the origin of the coordinate grid and express your answer using improper fractions in simplest form where needed.