In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

Ceva's theorem deals with lines constructed in these polygons, and Apollonius' theorem also deals with these polygons. The Euler line of one of them passes through several significant points, including the center of the nine-point circle. Their area can be calculated using Heron's formula. A fractal named for Sierpinski is based on these polygons, which have centroids, orthocenters, and circumcenters. For 10 points, name these polygons which may be scalene or equilateral.
Science