Answer:
B a = 180 -77-60
Step-by-step explanation:
The angles add to 180 degrees since they form a straight line
77+ 60+a = 180
a = 180 -77-60
The answer is B.
We know that the sum of angles in a straight line = 180°
Therefore:
77° + 60° + a = 180°
a = 180° - 77° - 60°
Hence, option B is the answer.
