Understanding Geometry is not strictly necessary before starting Calculus, but having a basic grasp of geometric concepts can be beneficial. While a foundational knowledge of trigonometric functions like sine, cosine, and tangent is essential for Calculus, students can progress without a formal Geometry course. However, Geometry enhances mathematical skills, particularly in proof construction, which is valuable in higher-level math. Students who study Geometry often gain insights into basic Trigonometry and Cartesian coordinate proofs, which can aid in Algebra and Calculus. Ultimately, the decision to study Geometry before Calculus may depend on individual educational goals and the specific curriculum being followed. Recommendations for Calculus I textbooks were also sought in the discussion.