HS Math Course is a term that refers to the three core math courses offered in high school: Trigonometry (TRIG), Geometry (GEOM), and Algebra (ALG). Trigonometry is a branch of mathematics that studies relationships between angles and sides of triangles. Geometry is the study of shapes, sizes, and relative positions of figures and their properties. Algebra is the study of mathematical symbols and the rules for manipulating them. Together, these three courses form the foundation of high school math education.