The Triangle Inequality Theorem states that the sum of any 2 sides of a triangle must be greater than the measure of the third side. Note: This rule must be satisfied for all 3 conditions of the sides
The triangle inequality states that the sum of the lengths of any two sides of a triangle is greater than the length of the third side. Therefore, if x is the third side, then 2+4>x, and x+2>4.
Therefore, x<6 and x>2, meaning that 2<x<6. The only choice that satisfies this is 5.
The correct answer is the Number line with points marked for seven, eight, nine, ten, eleven, twelve. The eight-point is marked with an open circle pointing right.