If one vertically opposite angle is acute, then the other will be obtuse.
If one vertically opposite angle is acute, then the other will be obtuse.
To solve this problem, we need to understand the properties of vertically opposite angles:
Given that vertically opposite angles are equal, if one angle is acute, the opposite angle must also be acute. This contradicts the statement in the problem that if one is acute, the other will be obtuse.
Therefore, the correct analysis of the problem reveals that the statement is incorrect.
Thus, the solution to the problem is False.
False