Parallel or Perpendicular

Front

What is the condition for two lines to be parallel?

Back

Two lines are parallel if they have the same slope (m).

Front

What is the condition for two lines to be perpendicular?

Back

Two lines are perpendicular if the product of their slopes (m1 * m2) is -1.

Front

If m1 = -1/2 and m2 = 1/2, are the lines parallel, perpendicular, or neither?

Back

Neither.

Front

If m1 = 7/5 and m2 = 5/7, are the lines parallel, perpendicular, or neither?

Back

Neither.

Front

Back

Parallel.

Front

Back

Perpendicular.

Front

Back

The slope is m.

Front

What does it mean if two lines have slopes that are negative reciprocals of each other?

Back

It means the lines are perpendicular.

Front

What is the slope of a vertical line?

Back

The slope of a vertical line is undefined.

Front

What is the slope of a horizontal line?

Back

The slope of a horizontal line is 0.