Similar scalene triangles are drawn on a coordinate plane. One triangle has side lengths of 1, 4, and 6. The other triangle has side lengths of 3 and 12, corresponding to the first triangle. Use the SSS criterion to determine the third side length of the corresponding triangle.
By using the SSS criterion, we can see that the ratio of corresponding side lengths of the two triangles is the same. Therefore, if the second triangle has side lengths of $3$ and $12$, corresponding to the first triangle, then the third side length of the second triangle must be $6 \cdot \frac{12}{4} = \boxed{18}$.
