Constructions

Supplies

Paper (thick stack)CompassStraight Edge

Congruent Line SegmentDraw a straight lineOpen compass where the point is on A and the pencil is on BPlace point on new end pointMake small arc on line

A

B

A

B

Draw point on arcResult: Congruent Line Segment

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Segment Bisector (_|_)Select compass size > ½ the line segmentPlace Point on A make large arcPlace Point on B make large arcLook for arc intersections

AB

Connect “X”s with Straight edgeResult: Perpendicular Bisector

A

B

Angle BisectorSet compassPlace point on vertexMake arc intersecting both sidesSet compass from intersection to intersectionMake small arc in the interior from each intersection

Draw a straight line from vertex through “X”Result: Angle bisector

Congruent Angles

Draw a lineMake arc on original angle (point on vertex)Make arc on new line

Point on end pointWith compass measure arc length from side to side

Draw line from new vertex through “X”Result: Congruent angles

How would you …

Double a line segment?Increase line segment by Half?

Make a 45 angle?A number line?Add two line segments together?Add two angles together?