1. とつめん   perpendicular lines   ray   convex   concave   Hint Half-n-half Clue   2. りょうけい、はすほうけい   parallel lines   rhombus   ellipse   segment   Half-n-half Clue   3. しちかっけい   concave   heptagon   segment   parallelogram   Half-n-half Clue   4. へいこうせん   parallel lines   vertex   pentagon   quadrangle   Half-n-half Clue   5. らんけい   concave   oval   vertex   polygon   Half-n-half Clue   6. はんきゅうたい   hemisphere   vertex   ray   quadrangle   Half-n-half Clue   7. ごかっけい   oval   heptagon   pentagon   rhombus   Half-n-half Clue