The Definition of Parallel Lines

Children learn about shapes and their unique characteristics. Parallel lines are further studied in geometry, and the concept is expanded in higher education for art, math and science. Parallel lines have a specific definition and discrete characteristics for identification.

Significance

Many objects have parallel lines and construction and design require understanding parallel lines for function. For example, tools such as levels quickly determine surfaces that are parallel to the floor.

Definition

In geometry, parallel lines are two or more lines that don't intersect.

Properties

Parallel lines maintain the same slope and distance from each other.

Identification

Parallel lines can be of infinite and varying lengths while maintaining equidistance and the same slopes. If lines are not the same length, the shorter one can be extended to determine parallel or transverse properties.

Misconception

Two lines can appear parallel if they are on different planes and are perpendicular to a center transversal. However, the two lines are not parallel; they are skew.

Fun Fact

Rays of light are considered parallel because even from a distant source, such as a star in space, they have minimal divergence.

References

• University of Cambridge NRICH Mathematics: Parallel Lines