Which of the following lists types of triangles?

The correct choice identifies types of triangles, which is crucial for understanding basic geometric classifications.

Triangles can be categorized based on their side lengths and angles. Equilateral triangles have all three sides equal, isosceles triangles have at least two sides of the same length, and scalene triangles have all sides of different lengths. This classification covers all variations in side lengths among triangles.

While the other choices include some correct terminologies, they also mention shapes or categories that are not types of triangles. For instance, trapezoidal refers to a type of quadrilateral, and angles like acute or obtuse can describe triangles but don't represent a complete classification of triangle types themselves. Therefore, the selection that lists equilateral, isosceles, and scalene clearly addresses distinct and universally recognized types of triangles.