A technician often has to sketch or design ductwork and the other parts of an HVAC system. Sometimes you have to sketch the room or building you are working with. This means working with lines, angles ...

Math equations can feel like a banal abstraction without images to make sense of the strings of numbers, letters, and Greek symbols. Consider the Pythagorean theorem, an essential relation in geometry ...

Most famous equation: Einstein's E = mc2, which means energy is equal to mass times the speed of light squared. Known digits of pi: More than 105 trillion digits Digits of pi NASA uses for equations: ...