What is the sum of the angles in a triangle?

The sum of the angles in a triangle is always 180°. This is a fundamental property of Euclidean geometry, which states that no matter the shape or type of triangle—whether it is scalene, isosceles, or equilateral—the internal angles will always add up to 180°.

This property can be derived from the fact that a triangle can be inscribed in a circle, or by using various theorems such as the angle sum property of polygons. In a triangle, if you extend one of the sides and create an exterior angle, the sum of the two adjacent interior angles will equal this exterior angle. When summed appropriately, this relationship illustrates that the three internal angles must total 180°.

Understanding this concept is crucial not only for solving basic geometry problems but also for grasping more complex concepts in higher mathematics.