Every angle or shapethat we come across in geometry or in the real
world is made up of intersecting lines. However, there are also two special
cases where lines do notintersect.
Parallel linesare coplanar lines that never intersect. Instead, they travel
similar paths at the same distance from each other at all times. Lines aand
bbelow in Figure 3.1 are parallel; the symbol used to represent parallel lines
is a||b. Another symbol used to indicate when two lines are parallel are
the corresponding arrows you see in the figure. Sometimes corresponding
tick marks are used instead of arrows.
Figure 3.1Parallel lines
a and ba
b