I started teaching in 1977, and across my nearly 50 years, I noticed that students were always interested in the history of ...

Parallel lines are indicated by arrows going in the same direction. If there is more than one set of parallel lines in a diagram, different numbers of arrows are used. The three lines in this ...

The symbol that represents corresponding angles ... This example occurs when two parallel lines are intersected by a third straight line. With both parallel lines cut, the adjacent angles and ...