 |
 +  +  =  (180°)1
= + 1
= + 1
= + 1
+ 1
+ 1
= 2 (360°) |
|
+ + = (180°)1
= + 1
= + 1
= + 1
+ 1
+ 1
= 2 (360°) |
1, 1, 1 angles
externes au triangle.