Final answer:
The '1turn-2turn rule' is related to the angle between the hour hand on a clock at 12 and 3 o'clock, which is 90 degrees or pi/2 radians.
Step-by-step explanation:
The question is asking about the concept of the '1turn-2turn rule'. The hint provided suggests that the rule can be treated as either the clock being on for 12 hours or operating at half-power for 24 hours, yielding equivalent answers. Unfortunately, the provided solution does not give a clear explanation of the rule. However, based on the given information, it can be inferred that the '1turn-2turn rule' is related to the angle between the hour hand at 12 and 3 o'clock, which is 90 degrees (or π/2 radians).