1, the outer angle of the triangle is greater than any inner angle that is not adjacent to it.
2. An outer angle of a triangle is equal to the sum of two non-adjacent inner angles.
The outer angle of a triangle is the angle formed by one side of the triangle and the opposite extension line of the other side. The sum of the three outer angles of a triangle is 360 degrees. Every vertex of a triangle has two equal external angles, so every triangle has six external angles. The outer angle of a triangle is greater than any non-adjacent inner angle, and the outer angle of a triangle is equal to the sum of two non-adjacent inner angles.
It is not adjacent to the inner corner.
Definition:
The included angle between one side of the inner angle of a triangle and the extension line of the other side. That is, "the adjacent complementary angles of the inner angles of triangles". Every vertex of a triangle has two equal external angles, so every triangle has six external angles.
The external angle theorem of a triangle is one of the important theorems in plane geometry, which means that one external angle of a triangle is equal to the sum of two internal angles that are not adjacent to it. It can be concluded that the outer angle of a triangle is larger than any inner angle that is not adjacent to it.
The sum of the internal angles of the triangle is equal to 180 degrees; The outer angle is greater than any non-adjacent inner angle and is equal to the sum of two non-adjacent inner angles. The sum of the outer angles of a polygon is 360 degrees, and the more the outer angles, the closer to the circle.