Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Lines in a plane that never meet and have the same slope.

Front

What are perpendicular lines?

Back

Lines that intersect at a right angle (90 degrees) and have slopes that are opposite reciprocals.

Front

What is the slope of a line?

Back

The steepness of a line, calculated as the rise over run (change in y over change in x).

Front

If two lines have the same slope, what can we say about them?

Back

They are parallel.

Front

If the slopes of two lines are opposite reciprocals, what can we say about them?

Back

They are perpendicular.

Front

What is the equation of a line in slope-intercept form?

Back

y = mx + b, where m is the slope and b is the y-intercept.

Front

How do you find the slope of a line given two points (x1, y1) and (x2, y2)?

Back

Slope (m) = (y2 - y1) / (x2 - x1).

Front

What is the y-intercept of a line?

Back

The point where the line crosses the y-axis (x=0).

Front

What does it mean for two lines to intersect?

Back

They cross each other at one point.

Front

What is the relationship between the slopes of two parallel lines?

Back

They have identical slopes.