Circumcenter  Centriod Incenter
Orthocenter   all four points together
Angle bisector instructions
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Instructions for constructing perpendicular bisectors and circumcenter.

The circles represent the arcs.
Create the intersections that you see here.
Start at point "A" and construct an arc (red circle) with racius of length "AC".
 

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Next start a point "C" and construct an arc of radius "AC" (second red circle).
 

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Note the intersection of the red circles or arcs, marked "D" and "E".  Construct a line "DE".



 
 

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To construct the second perpendicular bisector on "BC",
start at "C" and construct a arc (blue circle) with radius "BC".
 

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Construct a second arc (blue circle) from "B" to "C', with radius "BC".
 

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Note the intersection of the blue circlesor arcs, marked "F" and "G".  Construct a line "FG".
You have created an intersection between the red and blue perpendicular bisectors.
This is the circumcenter.
 

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To circumscribe the triangle use the circumcenter and one of the verticies of the triangle as your radius.
Construct a circle (yellow).



 
 

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Congratulations, you have just circumscribed the triangle.