Construction is a trillion-dollar enterprise that has been vital to the expansion of civilization throughout history; starting from the large and luxurious limestone pyramids of the ancient Egyptians, to the modern gigantic skyscrapers scattered around the world today; Most of these innovations incorporate three elements: timber, steel and concrete; Knowing how to use and maneuver these elements in a construction business, in a safe and resourceful manner, is a financially beneficial asset. For over 5 millennia man has built and designed buildings. Among the earliest recorded structures, the Egyptian pyramids are a great marvel, not only for their enormous size but also for their attention to precision, each piece of limestone having to be individually cut, brought to the site then lifted and placed in the correct position ("Chronology of Architecture"). The next important period in history is the Greek and Roman periods, when the Romans invented the bow. This construction element is still used today due to its extraordinary strength. The Romans also incorporated bricks used in place of stone, as well as domed roofs ("Architecture Chronology"). The new, now modern, building style we see today was introduced in 1972. It incorporated historic and familiar elements from previous architectural periods in history. For every construction project there are strict guidelines that must be followed in order for the structure to be legal. These guidelines are developed by the organization called Occupational Safety and Health Administration or OSHA ("Safety Color Guide"). OSHA has colors to coordinate where things go and how tools and materials will be used for specific applications. For example, ... half the paper ... serviced and when changing accessories, such as a drill bit, should not be plugged into an outlet due to the possibility of the tool being turned on and injuring someone. Tool safety is as important to the person observing the application of the tool as it is using it. For safety reasons, people observing the application must keep a safe distance and wear protective equipment ("Hand and power tools"). When you cut something or puncture something you should not wear loose clothing, ties or jewelery as they could get caught in the machine; furthermore, the material to be cut or drilled must be fixed to a stable and safe surface to avoid complications and injuries ("Hand and power tools"). Another very important risk to avoid would be for a worker to avoid keeping their finger on the power button while carrying a connected tool.