What is the sum of the angles in a triangle?

The correct answer is 180 degrees because, in Euclidean geometry, the sum of the interior angles of a triangle is always 180 degrees, regardless of the type of triangle—be it scalene, isosceles, or equilateral. This fundamental property of triangles can be visually demonstrated by drawing a triangle and extending one of its sides; the angles created on the exterior along with the interior angles will add up to a straight line, which is 180 degrees. This principle is foundational in geometry and is used extensively in various proofs and calculations related to triangles.