Understanding Parallel and Perpendicular Lines

This video tutorial explains how to use slope to determine if lines are parallel or perpendicular. It begins by defining parallel lines as having equal slopes and demonstrates this with examples. The video then introduces perpendicular lines, explaining that their slopes are opposite reciprocals, and provides examples to illustrate this concept. The tutorial also mentions an alternative method for finding slope using the slope formula.

What is the key characteristic of parallel lines?

• They intersect at right angles.

• They have the same slope.

• They have different slopes.

• They are always vertical.

How do you determine the slope of a line using a graph?

• By counting the rise over the run.

• By measuring the angle of the line.

• By calculating the area under the line.

• By finding the midpoint of the line.

In the first example, what is the slope of line A?

• 1/1

• 1/2

• 2/1

• 2/2

Which lines were determined to be parallel in the second example?

• Red and Green

• None of the lines

• Blue and Green

• Blue and Red

What is the slope formula when given ordered pairs?

• m = (x1 - x2) / (y1 - y2)

• m = (y1 - y2) / (x1 - x2)

• m = (y2 - y1) / (x2 - x1)

• m = (x2 - x1) / (y2 - y1)

What is the definition of perpendicular lines?

• Lines that have the same slope.

• Lines that are always horizontal.

• Lines that intersect at right angles.

• Lines that never meet.

What are the slopes of perpendicular lines?

• They are both negative.

• They are opposite reciprocals.

• They are both positive.

• They are equal.

If a line has a slope of 3/4, what is the slope of a line perpendicular to it?

• -4/3

• 4/3

• -3/4

• 3/4

In the example of determining perpendicular lines, what is the slope of line A?

• 1/2

• 2/1

• -1/2

• -2/1

Are the lines in the final example perpendicular?

• Yes, because they have the same slope.

• No, because they are not opposite reciprocals.

• Yes, because they are opposite reciprocals.

• No, because they do not intersect.