What is the sum of the interior angles of a triangle?

The sum of the interior angles of a triangle is always 180 degrees. This fundamental property arises from the geometric principles governing triangles in Euclidean space.

To understand this, consider that any triangle can be split into two right triangles by drawing a line from one vertex to the midpoint of the opposite side, thus illustrating how the angles relate to one another. The sum of the angles is directly related to the concept of parallel lines and transversals; when you extend one side of the triangle and consider the angles formed by a transversal, the relationship shows that all three angles in the triangle must combine to equal 180 degrees.

This property of triangles holds true regardless of the triangle's shape—whether it is scalene, isosceles, or equilateral—making it a universal rule in geometry. Other angles like 360 degrees, 90 degrees, or 270 degrees pertain to different geometric shapes or scenarios, such as quadrilaterals or various angles, and do not apply to the basic structure of a triangle.