1. concave   straight line   concave   prism   heptagon   Hint Half-n-half Clue   2. parallélogramme   straight line   vertex   parallelogram   plane   Half-n-half Clue   3. rebord   pyramid   concave   convex   edge   Half-n-half Clue   4. ovale   hexagon   parallelogram   oval   quadrilateral   Half-n-half Clue   5. hémisphère   prism   heptagon   hemisphere   parallelogram   Half-n-half Clue   6. Heptagon   concave   hexagon   heptagon   edge   Half-n-half Clue   7. lignes perpendiculaires   convex   edge   quadrangle   perpendicular lines   Half-n-half Clue