Final answer:
To answer which set of numbers could not represent the sides of a triangle, the Triangle Inequality Theorem is applied. Set C, which is {15, 27, 43}, fails this theorem because the sum of the shortest two sides is not greater than the length of the longest side.
Step-by-step explanation:
The student's question asks which set of numbers could not represent the sides of a triangle. To determine if a set of numbers can be the sides of a triangle, the Triangle Inequality Theorem is used, which states that the sum of the lengths of any two sides of a triangle must be greater than the length of the third side.
- Set A {15, 21, 33} passes the theorem as 15 + 21 > 33, 21 + 33 > 15, and 15 + 33 > 21.
- Set B {13, 27, 38} also passes as 13 + 27 > 38, 13 + 38 > 27, and 27 + 38 > 13.
- Set C {15, 27, 43} does not satisfy the theorem because 15 + 27 is not greater than 43.
- Set D {6, 15, 20} passes the theorem as 6 + 15 > 20, 6 + 20 > 15, and 15 + 20 > 6.
Therefore, set C is the one that could not represent the sides of a triangle.