Workkeys Math Practice Test

The sum of the angles in a triangle is always 180 degrees. This fundamental property holds true for all types of triangles—whether they are scalene, isosceles, or equilateral. The reason behind this is rooted in Euclidean geometry, which states that the angles of any triangle formed by three straight lines intersecting at three points will always add up to 180 degrees.

When you visualize or draw a triangle, if you were to extend one of its sides, the resulting exterior angle can be shown to equal the sum of the two opposite interior angles. By continuously applying this principle, you can see how every triangle will consistently maintain this angle total.

This property is crucial for solving various geometric problems and is foundational in higher mathematics, making it essential to remember. The other options, such as 90 degrees, 270 degrees, and 360 degrees, do not reflect the nature of triangles and thus do not apply in this context.