1. Geometric Constructions

2. Materials Needed Compass Protractor (straight edge) Pencil
Paper (white copy paper is best)
Pure constructions use COMPASS and STRAIGHT EDGE only!

3. Copying a Segment Construction #1 Given: Segment and point not on line
Measure the length with a compass
Using the same length, put tip on point and arc
Connect with straightedge

4. Copying an Angle Construction #2 Given: Angle and a ray
From vertex of angle, arc through angle
From endpoint of segment, same arc
Measure from intersection to intersection of angle
Using same measurement, from intersection on ray, draw an arc
Connect the dots

5. Bisect an Angle Construction #3 Given: an Angle
From the vertex, draw an arc
From each intersection, arc
Connect the dots
Video of angle bisector

6. Perpendicular Bisector
Construction #4
Perpendicular Bisector
of a Segment
Given: A segment
From each endpoint, arc above and below the segment
Connect the dots
Video of segment bisector

7. Perpendicular from a point
Construction #5
Perpendicular from a point
ON the line
Given: A line and point ON the line
From the point, arc left and right ON the line
From each intersection, arc above (or below) the line
Connect the dots
Video of perpendicular from a point ON line

8. Perpendicular from a point
Construction #6
Perpendicular from a point
OFF the line
Given: A line and point OFF the line
From the point, arc so that is hits the line twice
From each intersection, arc opposite the point
Connect the dots
Video of perpendicular from a point OFF line

9. Parallel Lines Construction #7 Given: A line and point OFF the line
Draw a transversal through the line
At that point, copy an angle from made by transversal and original line (construction #2)
Connect the dots
Video of parallel lines

10. Square Inscribed in Circle
Construction #8
Square Inscribed in Circle
Use compass to construct circle
Draw diameter
Construct perp. bisector of diameter
Connect 4 vertices with straightedge
Video of inscribed square

11. Reg Hex Inscribed in Circle
Construction #9
Reg Hex Inscribed in Circle
Use compass to construct circle
Measure radius of circle
Make 6 congruent arcs around circle
Connect 6 intersections
Video of inscribed hexagon

12. Equilateral Traingle Inscribed in Circle
Construction #10
Equilateral Traingle
Inscribed in Circle
Use compass to construct circle
Measure radius of circle
Make 6 congruent arcs around circle
Connect every other intersection