Parallel, Perpendicular, and Intersecting Lines

Front

What are parallel lines?

Back

Lines that never meet and are always the same distance apart.

Front

What are perpendicular lines?

Back

Lines that intersect at a right angle (90 degrees).

Front

What are intersecting lines?

Back

Lines that cross each other at any angle.

Front

When two lines are parallel, what can we say about their slopes?

Back

Their slopes are equal.

Front

When two lines are perpendicular, what can we say about their slopes?

Back

The product of their slopes is -1.

Front

Give an example of parallel lines in real life.

Back

Railroad tracks.

Front

Give an example of perpendicular lines in real life.

Back

The edges of a book.

Front

Give an example of intersecting lines in real life.

Back

The intersection of two roads.

Front

What is the symbol for parallel lines?

Back

|| (two vertical lines)

Front

What is the symbol for perpendicular lines?

Back

⊥ (a small square at the intersection)