1. 1.
2. 2. : ,
3. 3. .....................
4. 4. A B C D A BC D O ,AOC= BOD COB= AOD
5. 5. C DO A AOC+ AOD= =
6. 6. A O B D AOD+ BOD= =
7. 7. A O B D C AOC+ AOD= AOD+ BOD AOC= BOD( AOD ) , COB= AOD
8. 8. : : : , AOD = BOC
9. 9. P N QM O , PON = MOQ
10. 10.