Why Do Students Struggle in Geometry?

Some students have difficulties in mathematics in general. They find it difficult to comprehend the materials in most mathematics courses. However, more students appear to struggle in Geometry than in any other mathematics course. The reason is because Geometry is fundamentally different from most other mathematics courses.
Geometry is very different from Algebra I and Algebra II. For example, Geometry often requires students to visualize abstract objects. Students that are not visual learners therefore have difficulties mastering some Geometry concepts. It is much easier for most students to visualize a line than to visualize a polyhedron.
Another reason why students often struggle in Geometry is because Algebra courses often do not focus as much on proofs and reasoning as much as Geometry courses do. In many schools, students are first introduced to the ideas of axioms and postulates in Geometry courses. Algebra courses are often primarily based on memorization and basic equation solving strategies rather than proof formulations. Students who are already struggling with other Geometry topics feel an additional burden of trying to deduct these proofs.
Often, Geometry is taught in only one year while Algebra is taught in two years. Therefore, Geometry courses often have to teach many diverse topics in a short time period.
One solution to helping students better understand Geometry is to mix Geometry and Algebra courses. This would allow students to be able to both have more time to think about Geometric concepts as well as to learn some helpful Algebraic Geometry techniques. Another solution is to have a professional geometry tutor work with the student throughout the year.