Four critical areas of instruction in Geometry are:

1. Formally prove results about the geometry of the plane by using previously defined terms and notions

2. Explore similarity and congruence in greater detail, with an emphasis on geometric transformation, discovering trigonometric relationships and solving problems with right triangles

3. Explore the correspondence between the plane and the Cartesian coordinate system connecting algebra concepts with geometry concepts, including the study of right-triangle trigonometry and circles

4. Explore probability concepts and use probability in real-world situations

(California Mathematics Framework, 2013, p. 447)