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 triangles in Euclidean geometry. When you draw a triangle and label its angles as A, B, and C, you can demonstrate this by either folding the triangle or using parallel lines and alternate interior angles.

If you take any triangle, no matter the type (scalene, isosceles, or equilateral), when you add the measures of the three interior angles together, they will always equal 180 degrees. This property is essential for solving many geometric problems and serves as a foundation for understanding more complex concepts in geometry.

The other choices represent sums of angles that pertain to different shapes; for example, angles in a right triangle add to 90 degrees, while the sum of the angles in a quadrilateral totals 360 degrees. However, these properties do not apply to triangles, making 180 degrees the only correct answer for this question.