Question

Two lines intersect at a point, forming ​ ∠1 , ∠2 , ∠3 , and​ ​ ∠4 ​ .

Answer 1

The answer is:  [B]:  " 60° " .
________________________________________
Because at whatever location,  ∠2 and ∠4 are vertical angles;

and all vertical angles have equal measurements.

Given:   m∠1  is 120°, and ∠1 is supplementary to ∠2 ;

then m∠1 + m∠2 = 180° .

So, m∠2 = (180 - 120)° = 60° .

As aforementioned:

m∠4 = m∠2 = 60° ;  which is:  Answer choice:  [B]:  " 60° " .
___________________________________________________