What is the sum of the angles in a triangle?

In any triangle, the sum of the interior angles is always 180 degrees. This is a fundamental property of triangles in Euclidean geometry. When you take any triangle and measure each of its angles, you will find that when you add them together, they equal 180 degrees, regardless of the type of triangle—be it scalene, isosceles, or equilateral. This property is essential for solving various geometric problems involving triangles and is also foundational for understanding more complex geometric principles.

The other choices reflect different sums of angles found in various polygons or geometric configurations; for instance, a right angle measures 90 degrees, while a full circle is 360 degrees. But for triangles specifically, 180 degrees is the defining characteristic for the sum of its angles.