Parallel and Perpendicular lines

Front

What are parallel lines?

Back

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

Front

What are 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

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 negative reciprocals, what can we say about them?

Back

They are perpendicular.

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 = -2x + 1?

Back

The slope is 1/2.

Front

How can you determine if two lines are parallel using their equations?

Back

If the lines have the same slope, they are parallel.

Front

How can you determine if two lines are perpendicular using their slopes?

Back

If the product of their slopes is -1, they are perpendicular.

Front

What is the equation of a line parallel to y = 4x + 7 with a y-intercept of -2?

Back

y = 4x - 2.

Front

What is the equation of a line perpendicular to y = 1/3x + 2?

Back

y = -3x + b (where b can be any value).