Parallel, Perpendicular, or Neither?

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet. They are always the same distance apart and have the same slope.

Front

What are perpendicular lines?

Back

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

Front

What does 'neither' mean in the context of lines?

Back

'Neither' means that the lines are not parallel and do not intersect at a right angle.

Front

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

Back

If two 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 the slopes of two lines is -1, the lines are perpendicular.

Front

Example: Are the lines with equations y = 2x + 3 and y = 2x - 5 parallel, perpendicular, or neither?

Back

These lines are parallel because they have the same slope (2).

Front

Example: Are the lines with equations y = 3x + 1 and y = -rac{1}{3}x + 2 parallel, perpendicular, or neither?

Back

These lines are perpendicular because the product of their slopes (3 and -rac{1}{3}) is -1.

Front

Example: Determine if the line segments are parallel, perpendicular, or neither: Line 1: (1, 2) to (3, 4) and Line 2: (2, 3) to (4, 5).

Back

These lines are parallel.

Front

What is the slope of a line that is vertical?

Back

The slope of a vertical line is undefined.

Front

What is the slope of a line that is horizontal?

Back

The slope of a horizontal line is 0.