Geometry
posted by Lily on .
The perimeter of triangle ABC is 29 meters. Line segment AD bisects angle A. Find AB and AC. CD=5cm, DB=4 cm.(triangle angle bisector theorem)

AB/AC = 4/5 so AB = 4 AC/5
AB + AC + 9 = 29
so
AB + AC = 20
4 AC/5 + AC = 20
4 AC + 5 AC = 100
9 AC = 100
etc 
AC= 11.11111111
AB= 8.888888889 
You forgot to change 29m to 2900cm.

*The problem should say 29 cm.
AB/AC=4/5, so 4AC=5AB, which is also 4/5(AC)=AB.
AB+BC+AC=29
AB+AC+9=29
AB+AC=20
4/5(AC)+AC=20
9/5(AC)=20
AC=11 1/9
AB=20AC
AB=2011 1/9
AB=8 8/9