compass and straightedge construction of regular triangle
Draw an arc of the circle with center and radius .
Draw an arc of the circle with center and radius to find a point where it intersects the arc from the previous step.
Draw the regular triangle .
This construction is justified by the following:
This construction is based off of the one that Euclid provides in The Elements as the first proposition of the first book. Please see http://planetmath.org/?op=getmsg;id=15600this post for more details.
This construction also yields a method for constructing a angle using compass and straightedge.
Note that, with the exception of actually drawing the sides of the triangle, only the compass was used in this construction. Since regular triangles tessellate, repeated use of this construction provides a way to find infinitely many points on a line given two points on a line using just a compass.
If you are interested in seeing the rules for compass and straightedge constructions, click on the provided.
|Title||compass and straightedge construction of regular triangle|
|Date of creation||2013-03-22 17:19:10|
|Last modified on||2013-03-22 17:19:10|
|Last modified by||Wkbj79 (1863)|
|Synonym||compass and straightedge construction of equilateral triangle|
|Synonym||compass and straightedge construction of equiangular triangle|
|Defines||compass and straightedge construction of angle|