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1. Duplicating (copying) a segment2. Duplicating (copying) an angle3. Constructing the bisector of a segment (bisecting a segment)4. Constructing an angle bisector (bisecting an angle)5. Constructing a perpendicular bisector of a line segment6. Constructing a perpendicular from a point not on a line to the line(perpendicular lines)7. Constructing a line parallel to a given line through a point not onthe line
Topic 1Chapter 3: ConstructionsGreek philosopher PlatoEuclid(Elements)
1.(3.2)Constructing Perpendicular bisectors2.(3.3)Constructing perpendiculars to a line
(perpendicular from a point not on a line to the line)
3.(3.4) Constructing an angle bisectors (bisecting an angle)
4.(3.5) Constructing parallel linesthe line
3.2: Constructing the perpendicular bisector of a segment
Segment bisector: Is a line, ray, or segment that passes through the midpoint of a segment .
Textbook, page 149Patty Paper InvestigationInvestigation 1: Finding the right bisector
Textbook, page 150Investigation 2: Constructing thePerpendicular bisector
You Tube: Constructing the perpendicular bisector
https://www.youtube.com/watch?v=XXI60B3m70Y
If Line AC is the Perpendicular bisector of Segment PQ, then BP=BQ
Perpendicular Bisector Theorem: If a point is on theperpendicular bisector of a segment, then it is
equidistant from the endpoints.
Converse of the Perpendicular Bisector Theorem: If a point is equidistant from the endpoints of a segment , then it is on the perpendicular bisector of the segment.
If BP=BQ, thenLine AC is the Perpendicular bisector of Segment PQ.
3.3: Constructing Perpendiculars to a Line
Shortest Distance Theorem:The shortest distance from a point to a line is measuredalong the perpendicular segment from the point to the
line.
The distance from point Pto line AS is the length of segment PM.
Textbook, page 154Patty Paper InvestigationInvestigation 1: Finding the Right Line
Textbook, page 155Investigation 2: Patty-Paper Perpendiculars
You Tube: Constructing the perpendicular bisector
https://www.youtube.com/watch?v=I4dh2R6b1N0
Homework:Draw a line anda point not on the line.Construct the perpendicular from thatpoint to that line. Describe each step.
Textbook, page 159Patty Paper InvestigationInvestigation 1: Angle Bisecting by folding
Textbook, page 160Investigation 2: Angle Bisecting with compass
You Tube: Constructing an angle bisector
https://www.youtube.com/watch?v=2lP1NKYLKQw
How would you check whethertwo lines are parallel?
One way is to draw a transversal and compare corresponding angles
Textbook, page 163Patty Paper InvestigationInvestigation : Constructing parallel lines by folding.
You Tube: Constructing parallel lines usingcorresponding angles.
https://www.youtube.com/watch?v=im81vHIhZS8
https://www.youtube.com/watch?v=JI9IcdLI8WU