Answer:
C
Step-by-step explanation:
If you add up the length of two sides, the sum must be greater than the third side of the triangle.
If you add 1 and 2, it equals 3
But that means it will be equal to the length of the third side, 3
It will be impossible to make a triangle with those lengths of sides no matter how the sides or angles are set.
It's sort of difficult to explain this without any visual
You can look up "triangle inequality" to find out more about this
