The Triangle Inequality Theorem states that the sum of any two sides of a triangle must be greater than the third side.
Using this theorem, we can eliminate option 1 (8, 8, 20) because 8 + 8 is only 16, which is not greater than 20.
We can also eliminate option 4 (8, 4, 12) because 4 + 8 is only 12, which is not greater than 12.
Therefore, the answer is option 2 (10, 20, 15) and option 3 (20, 10, 30) because in both cases, the sum of any two sides is greater than the third side.
Apply the Triangle Inequality Theorem to determine which three side lengths form a triangle.
Pick one of the answers
1. 8, 8, 20
2. 10, 20, 15
3. 20, 10, 30
4. 8, 4, 12
1 answer