A triangle has corners points A, B, and C. Side AB has a length of #3 #. The distance between the intersection of point A's angle bisector with side BC and point B is #1 #. If side AC has a length of #4 #, what is the length of side BC?
2 Answers
Jun 11, 2016
Explanation:
Given
#In Delta ABC, AB =3,AC=4# #AD",the bisector of " /_BAC,"intersects BC at D" and BD=1# - We are to find out the length of BC
Construction
#CE" is drawn parallel to DA, it intersects produced BA at E"#
Now
-
# DA||CE,AC -"transversal"-> /_ DAC="alternate"/_ ACE# -
# DA||CE,BE-"transversal"-> /_ BAD="corresponding"/_ AEC# -
#But /_BAD =/_DAC,"AD being bisector of " /_BAC# -
#:.In" "DeltaACE,/_ACE=/_AEC=>AC=AE=4# -
#" Now "DA||CE->"BD"/"DC"="BA"/"AE"=3/4# -
#"BD"/"DC"=3/4=>1/"DC"=3/4=>DC=4/3# -
#BC=BD +DC=1+4/3=7/3#
Jun 11, 2016
Explanation:
According to the figure attached, using sinus law we have
so we have
Then we obtain