Author note — to cover
Chain point, straight-line, vertically-opposite, parallel-line, triangle and quadrilateral facts, stating a reason for every step, including algebraic setups and explain-why questions. This is where G6-style angle reasoning is rehearsed. Circle theorems are Higher pages in a later group; bearings journeys sit on Mensuration. Both tiers. (G3, G6)
Introduction
—coming soon—