Big Ideas Math Geometry, 2014
BI
Big Ideas Math Geometry, 2014 View details
5. Equations of Parallel and Perpendicular Lines
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Exercise 29 Page 161

To find the midpoint, we can use the Midpoint Formula.
Then we can use the midpoint to write the equation of the perpendicular bisector.

Finding the Midpoint

The coordinates of the given endpoints are and Let's use these to find the coordinates of the midpoint.
Simplify
The midpoint of is at Let's see what this looks like on a coordinate plane.

Finding the Perpendicular Line

To find the line that runs perpendicular to , we first need to find the slope of the segment. We can do this by substituting and into the Slope Formula.
Simplify right-hand side
Perpendicular lines have opposite reciprocal slopes. With this information, we know that all lines that are perpendicular to our given line will have a slope of
By substituting the midpoint into this equation for and we can solve for the intercept of the perpendicular line.
Solve for
Now that we have the intercept, we can complete the equation.
Let's graph the line.