What are the lengths of the angle bisectors?

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1 Answer
Feb 7, 2018

Bisector of /_A divides the opposite side BC(14) into segments BD=3 8/9 and DC=10 1/9 cms and bisector of /_C divides the opposite side AB(5) into segments AE=2.4 and EB=2.6 cms.

Explanation:

Sides of triangle are AB=5 , AC=13 , BC=14

Let the angle bisector of /_A, AD meets BC at D.

By the Angle Bisector Theorem we know,

(BD)/(DC)=(AB)/(AC) , let BD=x ; DC=y :. x/y=5/13

:. x= 5/13*y and x +y=14:. x= 14-y or

14-y = 5/13*y or (1+5/13)y= 14 or 18/13* y =14 or

y=(13*14)/18=(13*7)/9=91/9= 10 1/9 cm

:.x = 14-10 1/9= 3 8/9 cm. Therefore bisector of /_A

divides the opposie side BC(14) into segments

BD=3 8/9 and DC=10 1/9 cms. Similarly segments of side

AB and AC by the bisectors of /_B and /_C can be measured

in above method.

Let the angle bisector of /_C, CE meets AB at E.

let AE=x ; EB=y :. x/y=(AC)/(BC)=13/14

:. x= 13/14*y and x +y=5:. x= 5-y or

5-y = 13/14*y or (1+13/14)y= 5 or 27/14* y =5 or

y=(5*14)/27=70/27= 2 16/27~~2.6 cm .

:.x = 5-2 16/27= 2 11/27= 2.4 cm. Therefore bisector of /_C

divides the opposite side AB(5) into segments

AE=2.4 and EB=2.6 cms. [Ans]