Parallel and Perpendicular Lines

Front

What is the definition of parallel lines?

Back

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

Front

What is the definition of perpendicular lines?

Back

Perpendicular lines are lines that intersect at a right angle (90 degrees). The slopes of perpendicular lines are negative reciprocals of each other.

Front

What is the slope of a line with the equation y = 3x + 2?

Back

The slope is 3.

Front

If a line has a slope of 2, what is the slope of a line perpendicular to it?

Back

The slope of the perpendicular line is -1/2.

Front

What is the slope of a line that is horizontal?

Back

The slope of a horizontal line is 0.

Front

What is the slope of a line that is vertical?

Back

The slope of a vertical line is undefined.

Front

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

Back

The slope (m) is calculated as m = (y2 - y1) / (x2 - x1).

Front

What is the slope of a line that passes through the points (1, 2) and (3, 6)?

Back

The slope is 2.

Front

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

Back

They are parallel if m1 = m2.

Front

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

Back

They are perpendicular if m1 * m2 = -1.