College Math Placement Practice Test

What is the sum of the angles in a triangle?

1. 180 degrees

2. 90 degrees

3. 360 degrees

4. 270 degrees

The correct answer is: 180 degrees

In any triangle, the sum of the interior angles is always equal to 180 degrees. This fundamental property is true for all types of triangles, whether they are scalene, isosceles, or equilateral. To visualize this, you can imagine a triangle drawn on a flat surface. If you measure the three angles formed at each vertex of the triangle and add them together, you will always find that they total 180 degrees. This property is a key aspect of Euclidean geometry and is foundational for many other concepts in geometry and trigonometry. The other choices represent incorrect sums for triangles. For instance, a right angle measures 90 degrees, which is insufficient for a three-angle system. A sum of 360 degrees applies to a full circle, while 270 degrees does not correspond to any basic properties of triangle geometry. Thus, the sum of the angles being 180 degrees is the only correct answer when discussing the angles in a triangle.