Construction: Triangles

About Geometry Worksheet Activity 3D:  

 

Activity 3D is an introduction to construction of triangles.

 

Prerequisite Skills: Construct congruent line segments (Activity 1B).  Construct congruent angles (Activity 2A).

 

How to construct a triangle:

 

(Do problem 1 by following the steps below.)

 

1.   Adjust the compass opening (between point and pencil) to length AB.

 

2.   Place a point on the given construction line.  Label the point A.

 

3.   Place the compass at the point A.  Draw an arc that intersects the line.

 

4.   Place a point at the intersection of the arc and the line.  Label the point B.

 

5.   Adjust the compass opening (between point and pencil) to length AC.

 

6.   Place the compass point at point A.

    

7.   Draw a long arc (at least half a circle).  

 

8.   Adjust the compass opening (between point and pencil) to length BC.

 

9.  Place the compass point at point B.  Draw a long arc that intersects the other arc. 

 

10.   Place a point at the intersection of the arcs.  Label the point C.

 

11.  Use a straightedge.  Draw line segments AC and BC to make the triangle.

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