Start the lesson with a short tale to introduce the technical terms naturally: : A perfectly round Apple (or any simple sphere).
: The Apple is proud of its bright side, but on the side opposite the Sun, it wears a dark "velvet coat" called the Own Shadow . This shadow belongs specifically to the Apple and makes it look round and "heavy" instead of flat.
🎨 Lesson Concept: "The Brave Little Apple and its Shadow"