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 measure of the steepness of a line, calculated as the rise over run.

Front

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

Back

When m1 = m2.

Front

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

Back

When m1 * m2 = -1.

Front

What is the slope of the line represented by the equation y = mx + b?

Back

The slope is m.

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 equation of a line parallel to y = 2x + 3?

Back

y = 2x + b, where b is any real number.

Front

What is the equation of a line perpendicular to y = 2x + 3?

Back

y = -1/2x + b, where b is any real number.

Front

What is the slope of the line y = 4x + 3?

Back

The slope is 4.