Consider the enlargement of the triangle. A smaller triangle with side lengths 9 millimeters and 6 millimeters. A larger triangle with side lengths x millimeters and 16 millimeters.

Which statement is true about setting up a proportion to solve for the missing measure?
Corresponding parts must be in different positions.
Corresponding parts must be in the same position.
The two ratios are not equal.
The enlargement is not proportional to the original figure.