Because you mentioned the equator, that's part of the answer. The amazon is hot because it is by the equator. The equator is one of the hottest places on the earth because the sun's rays are very close to it or on it. That's why it's hot
it is so rainy because it gets more sunlight than other countrys closer to the equator believe it or not the amazon was a dessert a thousand years ago while the sahara was a rainforest but due to the earths change in rotation this reversed and so the amazon had more sunlight and so more rainforest sprang up.
