A=6 because 54/9=6
For b, the picture is not very clear and so I can’t see properly but if it says b/3 then b=45 because 15•3=45
c=11 because 23-12=11
Answer:

<h3>4th answer is correct</h3>
Step-by-step explanation:

<h2>Here we go ~ </h2>
According to given figure,


[ By linear pair ]

now, we can see that :

[ By Exterior angle property of Triangle ]


-6 and 6 is the answer to this