WOLFRAM|DEMONSTRATIONS PROJECT

Angle Bisectors in a Triangle

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E
H
K
angle
degrees
angle
degrees
CAM
36.57
BAM
36.57
ABM
27.70
CBM
27.70
BCM
25.73
ACM
25.73
segment
length
segment
length
DE
3.14
EF
3.14
GH
2.24
HI
2.24
JK
3.59
KL
3.59
The angle bisectors of a triangle ABC meet in a single point called the incenter. The incenter M is equidistant from the three sides of the triangle. The incenter is the center of the incircle, the largest circle inside ABC. The incircle is tangent to all three sides.
You can change the locations of E, H, and K on the angle bisectors.
If DE and EF are the perpendiculars from E to AC and AB, then |DE| = |EF|. Similarly, |GH| = |HI| and |JK| = |KL|.