Final answer:
The central idea of the text pertains to thermodynamics, specifically how heat transfer and material properties influence systems. Paragraph 6 likely discusses phase-change microcapsules in insulation, patent rights, or varieties of insulation fabrics, but the correct detail for development is unknown without the text.
Step-by-step explanation:
The central idea of the text is how heat transfer and the thermal properties of materials affect thermodynamics and are fundamental to understanding the behavior of various systems. In paragraph 6, the author likely uses details that either share that phase-change microcapsules can be incorporated into insulation, emphasize that Triangle had exclusive patent rights to phase-change microcapsules, or reveal that there are many different kinds of fabrics that can be used for insulation. Without the actual text from paragraph 6, it isn't possible to determine which of the three options is correct. However, it's clear that the central idea is developed through examples and explanations of how different materials and technologies like microcapsules or various fabrics interact with heat and transfer thermal energy.