| Triangles have been used throughout history. The Ancient Egyptians used triangles and angles to form their pyramids. However, there are other pryamids that are much, much smaller in crystals. YOu can see crystals in things that you use everyday such as sugar or salt. Each crystal in sugar and alt are shaped like cubes. Other types of crystals are tetrahedrons or square pyramids. They are found underground inminerals. When molten rock cooled and changed from a liquid to a solid, these minerals were formed. These crystals are used in diamonds and clocks. Even volcanoes have buildup of crystal on them after the somoke has risen. So as you can see, triangles and angles have been used in history and are in the crystals you can find in your everyday life. |