ABSTRACT
In 2005 Hurricane Katrina caused flooding and deaths as it made its way from the Bahamas to south Florida as a category 1 hurricane. Over the warm waters of the Gulf, it grew into a category 5 hurricane,
it had to a category 3 hurricane, the storm surges and destruction it created rates it as the most expensive hurricane to date, causing more than $45 billion of damage. Sadly it was also one of the deadliest, particularly for residents of New Orleans. In the hurricane image (Figure 2.1), air is moving rapidly, spiraling in a counterclockwise fashion. What isn’t so clear from this image is that the air moves faster as it approaches the eye of the hurricane. This air movement is best described by points and vectors: at any location (point), air moves in a certain direction and with a certain speed (velocity vector). This hurricane image is a good example of how helpful 2D geome-
try can be in a 3D world. Of course a hurricane is a 3D phenomenon; however, by analyzing 2D slices, or cross sections, we can develop a very informative analysis. Many other applications call for 2D geometry only. The purpose of this chapter is to define the two most fundamental tools we need to work in a 2D world: points and vectors.
