Why are aztec temples in the shape of a pyramid?
I’ve answered a simialar question before. They are technically ziggurats, as the first poster pointed out, but the stepped pyramid/pyramid/ziggurat shape is a common theme throughout the world. A lot of people will say that the pyramid is a basic geometric shape that is easy to build on a grand scale. But personally I think that civialisations predating the ancient Egyptians influenced cultures all over the world via a network of seafaring exploration and trade, that is why there are pyramids in Egypt, in South America, in Japan, Cambodia, basically all over the world. So I can say that it is a pyramid because it was the specific building shape required/desired by civilisations older than written history and they influenced other cultures to carry on this tradition, as to why they chose that specific shape themselves, noone may ever know.