1. 直線   straight line   edge   quadrangle   ray   Hint Half-n-half Clue   2. 六角形   hexagon   perpendicular lines   segment   prism   Half-n-half Clue   3. 菱形   rhombus   pyramid   concave   plane   Half-n-half Clue   4. 段   straight line   segment   concave   ellipse   Half-n-half Clue   5. 平行的線   heptagon   vertex   parallelogram   parallel lines   Half-n-half Clue   6. 飛機   pentagon   parallel lines   quadrilateral   plane   Half-n-half Clue   7. 橢圓   ellipse   convex   quadrangle   rhombus   Half-n-half Clue