This Stewart’s Theorem Lesson and Workbook is designed for students aged 14–18 studying Geometry at the secondary and higher secondary levels. Suitable for Grade 9–12 learners following O Level, IGCSE, GCSE, International GCSE, American High School, IB MYP, Matric, SSC, and similar national and international curricula, it serves both as a complete instructional lesson and a comprehensive practice workbook. Beginning with the concept of a cevian and the historical development of Stewart’s Theorem, the book guides students through clear explanations, visual geometric diagrams, a vector proof, worked examples, task cards, homework exercises, and answer keys. Special emphasis is placed on graphical visualization, geometric intuition, algebraic reasoning, and analytical problem-solving. The carefully designed diagrams help learners develop a stronger geometric vision, enabling them to connect abstract formulas with concrete geometric relationships. Whether used in the classroom, for self-study, revision, enrichment, or examination preparation, this resource provides a structured pathway from conceptual understanding to confident mastery of Stewart’s Theorem.