### Home > A2C > Chapter 4 > Lesson 4.2.4 > Problem 4-125

A line passes through the points

Find the slope of the line.

Plot the points on a graph. Find the slope (rise over run).

Find the slope of a line parallel to the given line.

Remember, parallel lines have the same slope.

Find the slope of a line perpendicular to the given line.

Remember, perpendicular lines form a right angle.

The slopes will be the negative reciprocals of each other.Find the product of the slopes.

Use the values from parts (b) and (c).

Make a conjecture about the product of the slopes of any two perpendicular lines.

The product of the slopes of two perpendicular lines is always the same number.

Test your conjecture by creating more examples.

Use the eTool below to explore the line.

Click the link at right for the full version of the eTool: A2C 4-125 HW eTool