Which best explains whether a triangle with side lengths 2 in., 5 in., and 4 in. is an acute triangle?

For a triangle with side lengths 2, 4, and 5, compare the square of the longest side with the sum of the squares of the other two. Since 2² + 4² = 20, which is less than 5² = 25, the triangle is obtuse, not acute. Choice C correctly describes this comparison.

AI-written and checked against the verified answer.