The deeply carved Maya relief sculpture depicting Shield Jaguar and Lady Xoc was created using the subtractive method of carving. This is very impressive when you consider that their tools were made of .

Stone/rocks

Explanation:

The deeply carved Maya relief sculpture depicting Shield Jaguar and Lady Xoc was created using the subtractive method of carving. This is very impressive when you consider that their tools were made of stone.  The Mayan used tools made of flint, obsidian, granite, limestone, and quartzite which are rocks/stones. Sculpting with such simple tools makes the Mayan art very impressive.

answer; unimodal and symmetrical;

answer; scientific method;