AngleBisector
✖
AngleBisector
gives the bisector of the interior angle at p formed by the triangle with vertex points p, q1 and q2.
Details

- AngleBisector gives an InfiniteLine object.
- The qi and p in AngleBisector[{q1,p,q2}] can be lists of coordinates or explicit Point objects.
- AngleBisector[p{q1,q2}] is equivalent to AngleBisector[{q1,p,q2}].
- AngleBisector gives the line that divides the angle into two equal angles and that passes through the point p.
- The following bisector type specifications "type" can be given:
-
"Interior" bisector of the interior angle of the triangle at p "Exterior" bisector of the exterior angle of the triangle at p - AngleBisector only works in 2D.
- AngleBisector can be used with symbolic points in GeometricScene.

Examples
open allclose allBasic Examples (1)Summary of the most common use cases
Scope (2)Survey of the scope of standard use cases
Properties & Relations (4)Properties of the function, and connections to other functions
AngleBisector finds the interior angle bisector by default:

https://wolfram.com/xid/0fq65i2z32j0u-ybhc


https://wolfram.com/xid/0fq65i2z32j0u-i7i7wo

The angle bisector divides the angle into two equal angles:

https://wolfram.com/xid/0fq65i2z32j0u-gda6u4


https://wolfram.com/xid/0fq65i2z32j0u-5iw9ao


https://wolfram.com/xid/0fq65i2z32j0u-201o02


https://wolfram.com/xid/0fq65i2z32j0u-3pml7s

The exterior angle bisector divides the exterior angle into two equal angles:

https://wolfram.com/xid/0fq65i2z32j0u-qlwr32


https://wolfram.com/xid/0fq65i2z32j0u-5u2htu


https://wolfram.com/xid/0fq65i2z32j0u-lm6ofl


https://wolfram.com/xid/0fq65i2z32j0u-zheqb4

TriangleConstruct[{a,b,c},"AngleBisector"] is equivalent to AngleBisector[{a,b,c}]:

https://wolfram.com/xid/0fq65i2z32j0u-qdoui3


https://wolfram.com/xid/0fq65i2z32j0u-m7u0mi

Possible Issues (2)Common pitfalls and unexpected behavior
The three points must be distinct:

https://wolfram.com/xid/0fq65i2z32j0u-8xpomj


AngleBisector only works in 2D:

https://wolfram.com/xid/0fq65i2z32j0u-119biw

Wolfram Research (2019), AngleBisector, Wolfram Language function, https://reference.wolfram.com/language/ref/AngleBisector.html.
Text
Wolfram Research (2019), AngleBisector, Wolfram Language function, https://reference.wolfram.com/language/ref/AngleBisector.html.
Wolfram Research (2019), AngleBisector, Wolfram Language function, https://reference.wolfram.com/language/ref/AngleBisector.html.
CMS
Wolfram Language. 2019. "AngleBisector." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/AngleBisector.html.
Wolfram Language. 2019. "AngleBisector." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/AngleBisector.html.
APA
Wolfram Language. (2019). AngleBisector. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/AngleBisector.html
Wolfram Language. (2019). AngleBisector. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/AngleBisector.html
BibTeX
@misc{reference.wolfram_2025_anglebisector, author="Wolfram Research", title="{AngleBisector}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/AngleBisector.html}", note=[Accessed: 05-June-2025
]}
BibLaTeX
@online{reference.wolfram_2025_anglebisector, organization={Wolfram Research}, title={AngleBisector}, year={2019}, url={https://reference.wolfram.com/language/ref/AngleBisector.html}, note=[Accessed: 05-June-2025
]}