- .
- 0 ˚<(a,α)<90˚.
l α , - α, - l;
1. ABCDA1B1C1D1 1 1, D=2. 11. (1).
: (1.):
+b+cz+d=0, a, b c .
, , : (1; 0; 0), 1(0;0;1), (0;2;0).
, b +b+cz+d=0: = -d, b= , c=-d. , , , 2++2z-2=0. , n .
:
.
: 45˚
- , , , .
- (0˚; 180˚)
- (0˚; 90˚].
- 0˚.
, - 1+1+1z+D1=0, - A2x+B2y+C2z+D2=0.
1. DA111D1 D1 D1FC, F- 11 11 .
: (0;0;0). , : (1;0;1), E(0;0,5;1), C(1;1;0), F(0,5;1;1). (A E), 1+1+1z+D1=0. :
∙0 + ∙0 + ∙0 +D =0;
∙1 + ∙0 + ∙1 +D =0;
∙0 + ∙0,5 + ∙1 +D =0.
, = - , = - 2, D= 0. , : +2 z =0.
, 1=1, 1= 2, 1= -1
(CF ), 2+2+2z+D1=0. :
∙1 + ∙1 + ∙0 +D =0;
∙1 + ∙0 + ∙1 +D =0;
∙0,5 + ∙1 + ∙1 +D =0.
, = , = 2, D = - 3. , :
2 + +z 3 = 0. , 2= 2, 2 = 1, 2= 1. :
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, 60̊. : 60̊.