1. 261 .
: D; D = D; K . : = K. |
D K D, K ; K = , D .
, = K ( ).
= K.
3. 269 .
: 268 .
IV. .
: . 35; 1213 . 90; 262, 264.
40
: ; ; .
I. .
1. .
2. .
3. :
1) 1 = = 90; 1 = 2. , = D.
2) 2 = D; = D, F = D = 90. , BF = ED; F = EC.
3) 3 1 = 2 = 90, = D. , = D.
4) 4 1 1 1 1 1; = 1 1; 1 = 2; = 1 1.
, = 1 1 1.
. 1 . 2
. 3 . 4
II. .
1. 263 .
2. 267 .
: .
III. ( ) (20 ).
I
1. 5 D = D; D = DF; 1 = 2 = 90. , .
2. 60, 18 . .
II
1. 6 1 = 2, 3 = 4 = 90; D = D. , .
2. , 15 . .
III ( )
1. . D. , = D.
2. D EF. CF FD, D = 18 , D = 30.
IV ( )
1. . , = .
|
|
2. = 60 . , = 6 .
. 5 . 6
IV. .
: 3035; ; . 36; 258, 265.
43
: ; ; .