What is the sum of all interior angles in a triangle?

The sum of all interior angles in a triangle is universally recognized as 180 degrees. This principle is foundational in geometry and arises from the properties of triangles.

When you consider a triangle, whether it is scalene, isosceles, or equilateral, the three angles within it will always add up to 180 degrees. This can be illustrated through various methods, such as drawing lines parallel to one side of the triangle and creating corresponding angles, which reinforces that the angles total to 180 degrees.

Understanding this property is crucial for solving problems related to triangles, especially in determining unknown angles or in proving other geometric theorems. It also serves as a basis for many more advanced concepts in geometry and trigonometry.