How many degrees are there in the sum of the interior angles of a triangle?

The sum of the interior angles of a triangle is always 180 degrees, regardless of the type of triangle (scalene, isosceles, or equilateral). This principle stems from the basic properties of triangles in Euclidean geometry.

To understand why the total is specifically 180 degrees, consider that if you take any triangle and extend one of its sides, you can create a straight line with the angle adjacent to the extended side. The angles thus formed (the two angles inside the triangle and the external angle) will add up to 180 degrees because they form a straight line. Since the two angles inside the triangle are also part of the triangle's interior angles, this reinforces the total sum of angles within the triangle itself.

Thus, the correct answer is 180 degrees, which accurately reflects this fundamental characteristic of triangles in geometry.