Respuesta :

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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]