I am a mathematician and I use many kinds of mathematics in my job. I teach university students who are going to be mathematics teachers so I use all the mathematics that you have seen and will see to the end of high school. I sometimes teach calculus to university students who are studying to be Engineers and statistics to students who are working toward a business degree.
Also in the Quandaries and Queries of Math Central we get questions in many areas of mathematics; arithmetic, algebra, geometry, calculus, statistics and more. We even get questions like why is lb the abbreviation for pounds, what do you call the line between the two numbers in a fraction, who first used the number zero.
If you are interested in what kind of career you can have with a math degree look at You Can Do THAT With a Math Degree?Good luck in your project,