1. plane   [bian;bian] yuan   fei ji   jin zi [da;ta]   si fang xing   Hint Half-n-half Clue   2. parallelogram   ping [hang;hang;heng;xing] si [bian;bian] xing   ping [hang;hang;heng;xing] [de;di;di] xian   [leng;leng;ling] jing   tuo yuan   Half-n-half Clue   3. pentagon   wu [bian;bian] xing   fei ji   duan dian   duo [jia;jiao;jue] xing   Half-n-half Clue   4. quadrilateral   si fang xing   tuo yuan   [liu;lu] [jia;jiao;jue] xing   qi [bian;bian] xing   Half-n-half Clue   5. concave   luan xing   [ao;wa] mian   [liu;lu] [jia;jiao;jue] xing   duo [jia;jiao;jue] xing   Half-n-half Clue   6. perpendicular lines   chui zhi xian   ping [hang;hang;heng;xing] [de;di;di] xian   [bian;bian] yuan   wu [bian;bian] xing   Half-n-half Clue   7. oval   duan dian   luan xing   ling xing   [bian;bian] yuan   Half-n-half Clue