4. Constructing Perpendiculars Through a Point

For Tuesday, 9/3/13, our topic is more on construction.

Lesson Objective (LO):  

SWBAT use constructions to explore attributes of perpendicular bisectors.

The two construction models we are doing are the following:  (Do these on the right side of your notebook)

1.  Constructing a perpendicular through a point on a line.

The first  half of this video:

http://www.teachertube.com/viewVideo.php?video_id=228903

Your job is to draw your own and write, in your own words, the steps needed to make this construction.

(Hint:  the first step is to draw a segment and put a point on it somewhere)

2.  Constructing a perpendicular through a point not on a line

This is the second half of the youtube video

Your job is to again draw your own and write, in your own words, the steps needed to make this construction.  (Hint:  the first step is to draw a segment and put a point somewhere above it.)

The final drawing for each of the above two tasks is going to look like this:

Class activity:  (Do this on the left side of your notebook)

1. Draw a triangle and on each side, construct its perpendicular bisector.  It's going to look like something like this:

Since the sides of your triangle won't be the same as above, your lines will be in different places.  But please note that each perpendicular bisector doesn't have to touch the opposite vertices.

2. Draw a triangle and on each side, construct a perpendicular line to the opposite vertex.  It's going to look something like below.  Yours, of course, can be different since your triangle will be different.  But please note that each line is perpendicular to the opposite point, which is the opposite vertex.