How to make Perpendicular lines.

Bisect
Bi- means two
Sect- means to cut
So bisect means to cut in two.

Directions:
1. Draw a line
2. Fold so pt A is on top of pt B.
3. Use a ruler to draw a line in the crease made by the fold.
4. Label the point where the two lines segments intersect P.
5. Measure the lengths of AP and BP
What do you noticed?
7. Use a protractor to measure the 4 angles created.
What do you notice? they are all 90*

You have created a perpendicular bisector
- a line that divides another line segment in half and is at right angles to it.
-equal line segments are marked with " hash" marks.



use a right triangle
1. Find the length of the line segment.
2. Determine the half way point.
3. Use right triangle to create a perpendicular line.


3rd way to make a perpendicular bisector.
use compass.



step one: make an arc from point A is greater then half way.
step two: make an equal sized arc intersections with a straight line, that line is a perpendicular bisector.


Draw a 12cm line segment label it PQ. Draw the perpendicular bisector of this line segment, all three was. Label the point where they intersect R.
a. what are the lengths of PR and PR?
b. what does it mean if the lengths are different?