Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

[Q]: Question: The length of a rectangular surface multiplied by its width is equal to what? Answer: area
[A]: The area of a rectangular surface is calculated as its length multiplied by its width.

[Q]: Question: What happens when an increase in temperature of a gas in a rigid container happens? Answer: pressure increases
[A]: An increase in temperature of a gas in a rigid container increases the pressure.

[Q]: Question: The frequency of a wave is the reciprocal of what other attribute of the wave? Answer: period
[A]:
The period of a wave and its frequency are reciprocals of each other.