1. hemisferio   convex   plane   perpendicular lines   hemisphere   Hint Half-n-half Clue   2. líneas paralelas   oval   quadrilateral   perpendicular lines   parallel lines   Half-n-half Clue   3. plano   parallel lines   plane   hexagon   ray   Half-n-half Clue   4. líneas perpendiculares   polygon   segment   perpendicular lines   ray   Half-n-half Clue   5. línea recta   convex   straight line   concave   quadrangle   Half-n-half Clue   6. cuadrilátero   perpendicular lines   polygon   quadrilateral   oval   Half-n-half Clue   7. rayo   quadrangle   oval   vertex   ray   Half-n-half Clue