1. pentagone   straight line   oval   pentagon   quadrangle   Hint Half-n-half Clue   2. Heptagon   ray   parallel lines   heptagon   ellipse   Half-n-half Clue   3. concave   polygon   convex   concave   rhombus   Half-n-half Clue   4. quadrilatère   ellipse   vertex   quadrangle   hexagon   Half-n-half Clue   5. lignes parallèles   straight line   vertex   pyramid   parallel lines   Half-n-half Clue   6. convexe   ellipse   perpendicular lines   convex   polygon   Half-n-half Clue   7. rebord   hemisphere   convex   pyramid   edge   Half-n-half Clue