Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Lines that never intersect 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 negative reciprocals of each other.

Front

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

Back

They are parallel.

Front

What is the slope of a line that is perpendicular to a line with a slope of 2?

Back

-1/2.

Front

What is the slope of a line that is parallel to a line with a slope of -3?

Back

-3.

Front

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

Back

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

Front

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

Back

2.

Front

If line a has a slope of 1/4, what is the slope of a line perpendicular to it?

Back

-4.

Front

What is the relationship between the slopes of two lines that are perpendicular?

Back

The product of their slopes is -1.

Front

If line b has a slope of 5, what is the slope of a line parallel to it?

Back

5.