Answer:
If AB and CD intersect at point P such that P is between A and B and is also between C and D, then ∠APC and ∠BPD are a pair of vertical angles.
Step-by-step explanation:
The diagram is a sketch of a counterexample. Notice that ∠APC and ∠BPD are actually the same angles and are not vertical angles.
If P is between A and B and is also between C and D, then ∠APC and ∠BPD are vertical angles. Then the statement can be completed as:
If AB and CD intersect at point P such that P is between A and B and is also between C and D, then ∠APC and ∠BPD are a pair of vertical angles.
