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 ...

Circles have different angle properties, described by a number of theorems. This is one of two guides on circle theorems, with this guide covering the following: the angle subtended by an arc at the ...

In our mind’s eye, the universe seems to go on forever. But using geometry we can explore a variety of three-dimensional shapes that offer alternatives to “ordinary” infinite space. When you gaze out ...