What is the sum of the angles in a triangle?

The sum of the angles in a triangle is always 180 degrees. This is a fundamental property of Euclidean geometry, which states that regardless of the type of triangle—whether it is scalene, isosceles, or equilateral—the total measure of the interior angles will add up to 180 degrees.

This conclusion can also be derived from various geometric principles, such as the fact that when a triangle is formed within a straight line, the exterior angle is equal to the sum of the two opposite interior angles, reinforcing that the overall sum remains constant at 180 degrees. This foundational concept is critical in many areas of geometry, providing a basis for solving problems related to triangles and their properties.