Final answer:
The third side x of a triangle with sides of length 5 and 12 must be greater than 7 and less than 17 according to the Triangle Inequality Theorem.
Step-by-step explanation:
To find the range of possible values for the third side x of a triangle when given two sides of lengths 5 and 12, we must apply the Triangle Inequality Theorem. This theorem states that the sum of the lengths of any two sides of a triangle must be greater than the length of the third side.
Therefore, we have two inequalities:
- 5 + 12 > x, which simplifies to 17 > x.
- 12 + x > 5 and 5 + x > 12, which simplify to x > 7 (from the second inequality).
To satisfy both conditions simultaneously, the value of x must be greater than 7 but less than 17.
Therefore, the correct answer is:
b) x must be greater than 7 but less than 17.