Answer: I think its SAS similarity theorem
Step-by-step explanation:
Okay so we know 2 sides of each triangle and an angle due to the vertical angle theorem.
So the side lengths are different but with some proportioning
12/20 = 6/10
so yes they are similar
and the angle in between the two sides lengths are congruent due to the vertical angle theorem
so 2 sides with an angle sandwiched btw is the SAS theorem
I hope this helped, let me know if you need some clarifying.
