This presentation teaches how to construct the perpendicular bisector of a line segment, the median of a triangle, and the centroid of a triangle. It includes video demonstrations of the construction steps and worksheets for practice. The goals are to learn the tools and techniques for these geometric constructions using a compass, straightedge, and pencil.

1. Click here to add slide title
Add text, video, or file here

2. Add Video title here
hover above to play video
Click here to return to last
slide viewed

3. Learning and Applying the
Perpendicular Bisector Construction

4. Goals and Tools
This presentation will demonstrate how to construct
• the perpendicular bisector of a segment
• the median of a triangle
• the centroid of a triangle
You will have opportunities to complete several constructions and will
need
• a compass
• a straightedge or ruler and pencil
• a printer and paper

5. Video Demonstration
hover above to play video
Click here to return to last
slide viewed

6. Written Procedure for Perpendicular Bisector
Construction

7. If the arcs don’t
intersect, start from
the last step with
your compass
opened wider

8. Your turn
Now it is your turn to try some constructions.
Try each problem from the worksheet titled
“Construction – Perpendicular Bisectors”.
The worksheet is also shown on the following
slide. If you need help, you can watch the
video again or follow the written instructions.
Click above Click above
to view to view
video written
instructions instructions

10. Solution
The blue marks are the arcs
made by the compass with
its point on each end of the
line segment – use a ruler
to draw the red line
connecting the arc
intersections.
Here, you are
constructing the
perpendicular bisector to
side AB

11. Video Demonstration
hover above to play video
Click here to return to last
slide viewed

12. Your Turn
Now it is your turn to try some constructions.
Try each problem from the worksheet titled
“Construct Medians of Triangles”. The worksheet is
also shown on the following slide. If you need help,
you can watch the video again.
Click above to
view video
instructions

14. Remember, you are
constructing the
perpendicular bisector
to the side of the
triangle that is opposite
of angle A

15. Video Demonstration
hover above to play video
Click here to return to last
slide viewed

16. Now it is your turn to try some constructions.
Try each problem from the worksheet titled
“Construct Centroids”. The worksheet is
also shown on the following slide. If you need
help, you can watch the video again.
Click above to
view video
instructions

17. All three medians should
intersect at one point –
the centroid!

19. After studying this presentation and practicing, you should be
able to construct :
• the perpendicular bisector of a segment
• the median of a triangle
• the centroid of a triangle
with thanks to:
Kuta Software for worksheets
http://www.mathopenref.com/index.html for construction videos
The
end