What are the principal techniques of sculpture? How are most public monuments made?

What are the principal techniques of sculpture? How are most public monuments made? What are some recent innovations in how sculptors work in space? What are the major types of clay? Who perfected metal inlays in the 13th century? What are the two major classifications of fiber art? What are the traditional methods of construction used in architecture? What impact has the development of high-strength structural steel had on architecture? How are environmental concerns affecting architecture today?