Question

Need to solve vertex angle​

Answer 1

Explanation:

I don’t know what was going on with those middle angles but adjacent angles must sum to 180 which 100 and 30 does not satisfy. The two upper angles must be (360-2(84))/2=96. It follows that the lower adjacent angles must be 180-96=84, just like the angles at top. Anyway the angle j must satisfy

j+2(84)=180

j+168=180

j=12 degrees