Answer:
A
Step-by-step explanation:
Since the 2 legs are congruent then the triangle is isosceles and therefore the base angles are congruent, that is
∠ 2 = [tex]\frac{180-120}{2}[/tex] = [tex]\frac{60}{2}[/tex] = 30° , thus
3x - 6 = 30 ( add 6 to both sides )
3x = 36 ( divide both sides by 3 )
x = 12 → A
