1. heptágono   heptagon   straight line   convex   parallelogram   Hint Half-n-half Clue   2. Viereck   quadrangle   ray   pyramid   parallel lines   Half-n-half Clue   3. Viereck   segment   heptagon   oval   quadrilateral   Half-n-half Clue   4. Prisma   concave   quadrilateral   prism   ray   Half-n-half Clue   5. Hemisphäre   ellipse   quadrangle   hemisphere   heptagon   Half-n-half Clue   6. Ellipse   concave   ellipse   plane   parallelogram   Half-n-half Clue   7. Konvex   convex   pentagon   ray   quadrangle   Half-n-half Clue