Fermat point

E146192

The Fermat point is a special point inside a triangle that minimizes the total distance to the triangle’s three vertices.

All labels observed (4)

Label Occurrences
Fermat point canonical 1
Fermat–Torricelli point 1
Fermat’s minimal path problem 1

How this entity was disambiguated

Statements (47)

Predicate Object
instanceOf geometric point
special point of a triangle
triangle center
alsoKnownAs Fermat point
surface form: Fermat–Torricelli point

Fermat point
surface form: Torricelli point
angleCondition construction with equilateral triangles valid when all angles of the triangle are less than 120 degrees
angleProperty forms 120-degree angles between segments to the vertices in an acute triangle
appliesTo triangle
barycentricCoordinates a·csc(A+π/3) : b·csc(B+π/3) : c·csc(C+π/3)
belongsTo set of triangle centers catalogued in ETC
category optimization in geometry
triangle geometry
constructionMethod intersection of lines from vertices to outer vertices of equilateral triangles constructed externally on each side
intersection of three lines each making 120 degrees with two sides of the triangle
coordinateSystem has known trilinear coordinates
definedIn Euclidean geometry
differenceFrom geometric median for more than three points
distanceProperty sum of distances from Fermat point to vertices is minimal among all points in the plane
ETCIndex X(13)
existenceCondition unique for any nondegenerate triangle
generalizationOf median point for three terminals in the plane
geometricProperty is the unique point where the three segments to vertices meet at 120 degrees in an acute triangle
historicalNote problem posed by Pierre de Fermat in the 17th century
invariantUnder rigid motions of the plane
similarity transformations of the triangle
liesOn lines joining each vertex to the opposite equilateral triangle vertex in the classical construction
locationProperty lies inside an acute triangle
lies on a vertex of an obtuse triangle
namedAfter Evangelista Torricelli
Pierre de Fermat
optimizationProperty gives minimal network length connecting the three vertices with one Steiner point
minimizes sum of distances to the three vertices of the triangle
relatedConcept Fermat's Last Theorem
surface form: Fermat problem

Steiner tree problem
geometric median of three points
relatedTo Fermat point self-linksurface differs
surface form: Fermat’s minimal path problem
relatedTriangleCenter centroid
circumcenter
incenter
orthocenter
solvedBy Evangelista Torricelli
specialCase coincides with the obtuse vertex when the triangle has an angle of at least 120 degrees
symmetryProperty symmetric with respect to permutations of the triangle’s vertices
trilinearCoordinates csc(A+π/3) : csc(B+π/3) : csc(C+π/3)
usedIn facility location problems
geometric optimization
network optimization

How these facts were elicited

Referenced by (4)

Full triples — surface form annotated when it differs from this entity's canonical label.

Pierre de Fermat notableWork Fermat point
Fermat point alsoKnownAs Fermat point
this entity surface form: Torricelli point
Fermat point alsoKnownAs Fermat point
this entity surface form: Fermat–Torricelli point
Fermat point relatedTo Fermat point self-linksurface differs
this entity surface form: Fermat’s minimal path problem