Question

Why are chairs made up of thermosetting plastics?

Answer 1

Thermosetting plastics are very strong than any other plastics. They can't be remolded. Chairs are made for the reason that they can't be broken easily. And chairs made up of thermosetting last many days. 

Answer 2

chairs are made up of thermosetting plastic  because  the chairs should be strong enough to fullfill their purpose and not to melt