The term for the angle required to form a triangle is called a "triangle angle" or more specifically, the "sum of interior angles." In Euclidean geometry, the sum of all interior angles in any triangle is always 180 degrees. Each individual angle can vary depending on the type of triangle—whether it’s scalene, isosceles, or equilateral. Understanding triangle angles is foundational in various areas of mathematics, including trigonometry, and plays a significant role in solving various geometric problems. This property of triangles is essential for both theoretical mathematics and real-world applications like engineering and architecture.