1. 直線   rhombus   straight line   segment   parallelogram   Hint Half-n-half Clue   2. 垂線　   parallelogram   ellipse   straight line   perpendicular lines   Half-n-half Clue   3. 六角形   polygon   hexagon   pentagon   segment   Half-n-half Clue   4. 七角形   perpendicular lines   heptagon   ray   oval   Half-n-half Clue   5. 光線，   heptagon   plane   ray   segment   Half-n-half Clue   6. 長円   hemisphere   hexagon   ellipse   rhombus   Half-n-half Clue   7. 四角形   convex   edge   quadrangle   ray   Half-n-half Clue