Parallel and Perpendicular Lines

Front

Slopes of parallel lines are...

Back

the same.

Front

What slope is perpendicular to: m = 3?

Back

-1/3

Front

What slope is perpendicular to: m = 5/8?

Back

-8/5

Front

Slopes of perpendicular lines are...

Back

negative reciprocals.

Front

What slope is parallel to: m = 4?

Back

4

Front

Definition of parallel lines in geometry.

Back

Lines that never intersect and have the same slope.

Front

Definition of perpendicular lines in geometry.

Back

Lines that intersect at a right angle (90 degrees).

Front

If the slope of one line is m, what is the slope of a line perpendicular to it?

Back

The slope is -1/m (negative reciprocal).

Front

Example of parallel lines: y = 2x + 3 and y = 2x - 5. Are they parallel?

Back

Yes, they have the same slope (2).

Front

Example of perpendicular lines: y = 1/2x + 1 and y = -2x + 3. Are they perpendicular?

Back

Yes, their slopes (1/2 and -2) are negative reciprocals.