Respuesta :

Answer:

36

Step-by-step explanation:

As the triangle ABC is isosceles so A and B has the same measures

And, the sum of the angles is 180°.

Therefore 2 times the measure of angle

B plus  120° = 180°,

So, the equation:

2x + 120 = 180

So x = 30

Now we have to apply the law of sin on the triangle BMC as shown below:

[tex]\frac{12}{\sin30} = \frac{BC}{\sin 60}[/tex]

Now calculate for BC

BC = 20.7

We use the law of sin again i.e

[tex]\frac{AB}{\sin 120} = \frac{20.7}{\sin 30}[/tex]

So AB is 36

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