GIS Projections Part 1

Good Day GIS'ers and people who randomly found there way here.
This post will be all about map Projections based on this weeks Intro to GIS assignment on the same. This is a two part theme with part one being this week with the second part to come later. some key learning objectives are below

• Recall the basis in which projected and geographic coordinate systems are measured
• Add geographic data and observe software rules and “on-the-fly” functions while adding data with and without a defined coordinate system to a map data frame
• Utilize the Project tool in ArcGIS to reproject a data layer to a common Projected Coordinate System
• Visualize data being displayed in three different projected coordinate systems on a single map and note the differences
• Quantify the difference in area (square miles) between data being displayed between three different projected coordinate systems

 So lets break down a couple of the above. First, this lab was done entirely in ArcGIS Desktop, and its purpose was to display the same data set (size of Florida and its counties) under different projections or coordinate systems. A map projection is a transformation of the 3-dimensional (globe) earth into a 2-dimensional flat map. There are many ways to accomplish this projection, and you can then add many different coordinate systems to it. I wont go more in depth with that here. The lab took county data for Florida and had me change the projection from one projected coordinate system, (that is a coordinate system designed for a flat surface) to another. It also had me observing what and how this is done in ArcGIS Desktop. This is finally portrayed for you the map user to see by showing the same mapped area, in three different projections, highlighting counties across the state as an example, and showing their measurement in square miles compared to each other. See below:

Upon looking at this map you can see that right away, they are essentially 3 of the same map minus the color change to set them apart. The projection used is highlighted at the top of the otherwise identically laid out maps. When you look a little further you can see the same four highlighted counties in each map, and a little closer still shows that the square mileage is slightly different in each. you can see that in the extreme from one projection to the next an entire county is different by 19 square miles. All of this is due to the projection type used and where its origin lies in reference to the map. This can also show you a good reason of why its important to make sure that all the data you gather for a project is in a usable format or can be changed to suit your needs. 
I hope you enjoy referencing the above and at least learned something about map projections. Did you notice the subliminal patriotism?