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BD bisects <ABC.
m <ABD= 2.5x + 8.6
m<CBD = 3.5x - 3.4
Find m<ABC
Answer:
[tex]m\angle ABC = 77.2^\circ[/tex]
Step-by-step explanation:
We have an angle ABC and a line BD bisecting it.
If an angle is bisected, then the two formed angles are congruent, that is
[tex]m\angle ABD=m\angle CBD[/tex]
Substituting the algebraic expressions for both angles:
[tex]2.5x + 8.6=3.5x - 3.4[/tex]
Subtracting 8.6 and 3.5x:
[tex]2.5x - 3.5x = -8.6 - 3.4[/tex]
Operating:
[tex]-x = -12[/tex]
[tex]x = 12[/tex]
The two angles are:
[tex]m\angle ABD=2.5x + 8.6=2.5(12) + 8.6=38.6^\circ[/tex]
[tex]m\angle CBD=3.5x - 3.4 = 38.6^\circ[/tex]
As expected, both angles have the same measure.
The measure of the total angle ABC is twice any of those:
[tex]m\angle ABC = 2*38.6^\circ=77.2^\circ[/tex]
[tex]\mathbf{m\angle ABC = 77.2^\circ}[/tex]