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 in Euclidean geometry. Regardless of the type of triangle—be it scalene, isosceles, or equilateral—the angles will always add up to this consistent total.

This property can be derived from the concept of parallel lines and transversals or can be visualized by dividing a triangle into smaller segments. For instance, if you draw a line parallel to one side of the triangle through the opposite vertex, this creates alternate interior angles that help illustrate how the angles relate to each other.

In contrast, the other options represent angle sums that do not apply to triangles. For example, 360 degrees is the total measure of angles in a full circle, 90 degrees corresponds to the angle of a right angle, and 270 degrees does not relate to the angles of a triangle in any geometric context. These distinctions emphasize the unique characteristics of triangles and their internal angles.