Answer: Last Option
Step-by-step explanation:
By definition the sum of the internal angles of a triangle must always be equal to 180 °.
This means that:
Now we solve the equation for the variable x
We subtract 12 in both barks of the equation
Divide by 3 on both sides of the equation
Finally the measure of angle ABC is: (56-5)° = 51°
Answer: 29
Step-by-step explanatio?