1
1: Cho 



.



  , AC
= b ,

0
C 60
. () 




0
30
.
1/ 
2/ .
2: 



 .










 .
3/
xq
S
.
3:  .
4: 

.ABCD.
1/=



























,.
i 6:  2a, 





, 







0
30

1/
xq tp
S va S
.
2/ .
3/ .
8: 


















R3
.




.
1/
xq tp
S va S
.
2/ .
9: 







































 ,





0
60
.
1/ .
2
2/
3/ .
12: 


.
2/ 
()
theo R ,

.










 ?
13: .





, 


.
1/ .
2/ 
tan


















.
1/ .
2/
xq
S
 .
3/
tp
S
.
15: 




0
BAA' 45
.
1/C/







 .
2/
xq
S
.
17: 









.




3/  .c


5 

S,A,B,C,D.
18:   

.









 ,











..
20: 





.









 .nh SA






.










1 

.
22: 







 .

AB =a,BC =2a ,=a.




 AM =3MD.
1/ 
2/ 
23: 









 ,








.=h, AB =a, CD =





2 






0
60
..
25: 




 .

29: 



.ABC.





,SB,

3 

,
, 



.C/m :
S.A'B'C'
S.ABC
V
SA' SB' SC'
. . .



 .ABC =5a ,BC=6a ,CA=7a.
SAB,SBC,










0
60
. .
32: 



.









..
33: 







 .ABCD ,







 ,

0
60
.  

.













ABC
, 








F.
35: 



 ...
,





 BC.
1/.



=a ,








AB =BC =a.  ,










ABC
.
1/ .ABC.
2/C/m :
SC mp(AB'C')
.
3/
37: 

AH SB

SB mp(AHK)
.
3/ .AHK.
38: 





 .














=a ,BC =2a ,=3a .

(P) 









, AB =a,
AC a 3
 (ABC)
 ..






2 



 
 40: C



.




,DN.
i 41:



.







 ,AB=BC=a,

AA' a 2
.





 .
.










 





.,N,












,BC,CD.C/m :
AM BP
.
 43:





 ,






. C/m :
MN BD
 2 





.
5
 44:



.







 ,

2  , 


.







 , 








= 2a ..
 46:



.



 =a ,

.
 47:





 .









 , SA =2a

SA mp(ABC)
.,


























1 

..
 50: Cho 1  .





=





.











.











 .
1/C/










 .ABC .










 ,











1 




 .

1 



AB=AC =



A2
.  3 

,B,





( ABC) 

.

xq
S


