Given the task definition and input, reply with output. 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.

According to Turan's Theorem, one of these entities is necessarily formed if four times the number of edges in a graph is greater than the number of vertices squared. Every two-coloring on a complete 6-graph forms two monochrome examples of these entities. Three lines concur in one of these figures if the conditions for Ceva's ["CHAY-va's] Theorem are met, and the areas of these figures can be found using (*) Heron's formula. The laws of sines and cosines hold true for these shapes, whose areas are equal to base times height over two. For ten points, name these three-sided figures, which come in equilateral and isosceles varieties.

Science