Unit 2 Lesson 8 Construct a Perpendicular Bisector
Construct a Perpendicular Bisector!
Construct a Perpendicular Bisector
Select "Zoom Out" and click in the middle of the box to zoom out. *
Using the Geogebra applet above, use the following steps to create a perpendicular bisector.
1. Create a circle by hovering on the circle tool, clicking on the compass and clicking on A then point B, then point B again.
2. Create another circle by hovering on the circle tool 
Click on the compass and clicking on point B then point A, then point A again.
3. Hover over the point icon 
and click on intersect. Click on one circle, then click on the other circle, two points should be made.
4. Hover over the line icon 
and click on the line segment tool to connect those two points where the circles intersect.
5. Use the point icon and use the intersection tool and click on Segment AB and the line that you just drew, CD.
6. Connect the top intersection point to Point A and Point B using the segment tool.
a. Using the angle tool above 
measure by clicking point B then the midpoint then the top intersection point. How many degrees is that angle?
b. Using the angle tool, measure by clicking the top intersection point then the midpoint then A. How many degrees is that angle?
c. To measure the length of the segments cut, hover over the angle tool, then click on the distance tool. Click on A then click on the midpoint. Click on B then click on the midpoint. What do you notice about the measures?
d. Given your measures above, why do you think the line segment you created is called a perpendicular bisector? (In other words what does perpendicular mean and what does bisector mean?)
Investigating the Perpendicular Bisector
1. Use the measure distance length tool (under the angle icon) to measure the distance between the top intersection point and point A. Then measure the distance between the top intersection point and point B. What are the two distances?
2. Add 3 more points to line CD. Repeat the same process above, using the measure tool to measure the length of each new point to A and B. List each distance below.
Exit Ticket
Given above, finish the following sentence: A point is on the perpendicular bisector of AB if the point is..