1. 立方体   rectangle   radius   cube   cone   Hint Half-n-half Clue   2. 正方形   square   cube   angle   radius   Half-n-half Clue   3. 区域   line   rectangle   area   angle   Half-n-half Clue   4. 曲线   cylinder   curve   perimeter   rectangle   Half-n-half Clue   5. 球形   diameter   curve   cone   sphere   Half-n-half Clue   6. 角度   diameter   sphere   triangle   angle   Half-n-half Clue   7. 圆周   side   curve   circle   circumference   Half-n-half Clue