A pyramid is a three-dimensional geometric shape that has a flat base and triangular sides that meet at a point called the apex. The most famous pyramids are the Egyptian pyramids, which were built as tombs for pharaohs. These structures are known for their impressive size and precise construction, showcasing the advanced engineering skills of ancient civilizations. Pyramids can also be found in other cultures, such as the Mesoamerican pyramids built by the Maya and Aztec civilizations. These pyramids often served as temples for religious ceremonies. The pyramid shape is also used in various fields, like the food pyramid, which helps people understand a balanced diet.