Question

I need to know if it’s a b c or D

Answer 1

Notice that AD is a diameter, therefore,

$x+y+55=180$

Furthermore, arcAB=25° and x° is the central angle that defined arcAB; thus, x°=25°.

Finally,

$\begin{gathered} \Rightarrow25+y+55=180 \\ \Rightarrow y=180-55-25=100 \\ \Rightarrow y=100 \end{gathered}$

Thus, the answer is y=100