Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet. They have the same slope.

Front

What are perpendicular lines?

Back

Perpendicular lines are lines that intersect at a right angle (90 degrees).

Front

If two lines have slopes m1 and m2, when are they parallel?

Back

Two lines are parallel if m1 = m2.

Front

If two lines have slopes m1 and m2, when are they perpendicular?

Back

Two lines are perpendicular if m1 * m2 = -1.

Front

What is the slope of a line parallel to y = 3x + 5?

Back

The slope is 3.

Front

What is the slope of a line perpendicular to y = -1/2x + 4?

Back

The slope is 2 (the opposite reciprocal of -1/2).

Front

What does the slope of a line represent?

Back

The slope represents the rate of change of y with respect to x.

Front

How do you find the slope from two points (x1, y1) and (x2, y2)?

Back

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

Front

What is the slope of the line y = 4x - 1?

Back

The slope is 4.

Front

If a line has a slope of 0, what does that mean?

Back

A slope of 0 means the line is horizontal.