Answer:
The Incas used huge blocks of stone for their buildings.
Explanation:
Hello. You did not report the National Geographic article to which this question refers, which makes it impossible for this question to be answered accurately.
However, there is much evidence that the Incas used huge blocks of stone that they cut out in extremely precise shapes to promote a perfect fit between each block. These blocks were what allowed the Incas to build walls, fortresses, houses, among other things. These blocks were extremely efficient and allowed the construction to be carried out even without elements such as iron, steel and wheels.
