The conversation between human and AI assistant.
[|Human|] What is the name of the theorem that states that a triangle's angles always add up to 180°?
[|AI|] The theorem you are referring to is called the Triangle Sum Theorem. This theorem states that the sum of the three interior angles of a triangle is always equal to 180°.
[|Human|] 
What is the name of the theorem that states that a triangle's angles always add up to 180°?