X=12. So this one says that it has 3 congruent sides so therefore it has to have 3 congruent angles. Here we have angle 2 and we have angle 60. Given the definition of triangle congruence, we can say that 60 is angle 2 and that the third angle is also 60 but it’s not relevant in this problem. So knowing that angle 2 is 4x+12 we solve for x by seeding that equal to 60 and then solving for x we get x=12. Hope this helps!!!!
