"When am I ever going to use this?"
Many students will ask this question at some point throughout their initial high school experience.
Reason #1: Because it requires work and discipline. Algebra sharpens your ability to make connections. It lays the foundation for what may lie ahead. Someday you will probably need to work with formulas, charts, tables, etc. You cannot do this without being confident working with variables, numbers and they way they interact with each other. Geometry involves spatial reasoning. It can be involved in almost everything around you: art, engineering, architecture, sports, etc.
Reason #2: Algebra is an abstract discipline. This causes the brain to think in totally new patterns which causes the brain to work (like a muscle). The more that muscle is worked, the stronger it will be to perform any task. Basically, algebra builds a better brain. "When the brain is stimulated, the hair-like dendrites of the brain grow more extensive and more complex enabling more connections with other brain cells. We often hear that we use only a small percentage of our brain's capacity. The study of algebra is a way to increase our use of this marvelous muscle. By studying algebra, more "highways" are "built" upon which future "cargo" is transported -- cargo other than algebra." (http://www.mathmedia.com/whystudal.html) Geometry provides a connection between both sides of your brain. The left-brain is the more logical, technical side, but the right-brain is the part that visualizes and where most artist gets their creative inspiration. It is not common to have the ability to make the two sides of your brain connect and work together as one, but Geometry will assist in doing that.