1. quadrangle   shikakkei   oumen   totsumen   heikoushihenkei   Hint Half-n-half Clue   2. oval   rankei   suisen   totsumen   oumen   Half-n-half Clue   3. quadrilateral   ryoukei、hasuhoukei   shichikakkei   shihenkei   chokusen   Half-n-half Clue   4. concave   oumen   hankyuutai   heimen   rankei   Half-n-half Clue   5. straight line   chokusen   fuchi、hashi   kukiri,bubun   heikousen   Half-n-half Clue   6. edge   fuchi、hashi   gokakkei   shikakkei   oumen   Half-n-half Clue   7. parallel lines   ryoukei、hasuhoukei   totsumen   chokusen   heikousen   Half-n-half Clue