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BD bisects m m Find m

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The text of the question is not visible in the answering window. I'll reproduce it here:

BD bisects <ABC.

m <ABD= 2.5x + 8.6

m<CBD = 3.5x - 3.4

Find m<ABC

Answer:


m\angle ABC = 77.2^\circ

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


m\angle ABD=m\angle CBD

Substituting the algebraic expressions for both angles:


2.5x + 8.6=3.5x - 3.4

Subtracting 8.6 and 3.5x:


2.5x - 3.5x = -8.6 - 3.4

Operating:


-x = -12


x = 12

The two angles are:


m\angle ABD=2.5x + 8.6=2.5(12) + 8.6=38.6^\circ


m\angle CBD=3.5x - 3.4 = 38.6^\circ

As expected, both angles have the same measure.

The measure of the total angle ABC is twice any of those:


m\angle ABC = 2*38.6^\circ=77.2^\circ


\mathbf{m\angle ABC = 77.2^\circ}

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