When do three side lengths measures form a triangle?

Three side lengths can form a triangle if they satisfy the triangle inequality theorem, which states that the sum of the lengths of any two sides must be greater than the length of the third side. This must hold true for all three combinations of the side lengths. For example, if the side lengths are (a), (b), and (c), then (a + b > c), (a + c > b), and (b + c > a) must all be true. If any of these conditions are not met, the side lengths cannot form a triangle.