Answer:
Well i am not sure on that but i do know that the angle measures have to add up to 180 degrees hope that helps at least a little
Step-by-step explanation:
That would be the first choice, the transitive property of congruence
How did I get it? I just know my properties of relations:
The usually definitions apply to equality; congruence is essentially the same thing.
Reflexive Property: a=a
Symmetric Property: If a=b then b=a
Transitive Property: If a=b and b=c then a=c
When a relation is reflexive, symmetric and transitive it is called an equivalence relation and it divides the elements into equivalence classes.
Distributive Property. There is no distributive property of equality or congruence. The distributive property of multiplication over addition states: a(b+c)=ab+ac.
Answer
x=-40
hope this helps and have a wonderful day :)