In the Figure,? and ? Are Positive Angles $\frac { 1 } { 2 }$

Multiple Choice

In the figure,? and ? are positive angles.? ? a = 9,b = 18
Write ? as a function of ?.
?

A) ? = arcsin(9sin?)
B) ? = sin( $\frac { 1 } { 2 }$ sin?) ?
C) ? = arcsin( $\frac { 1 } { 2 }$ sin?)
D) ? = sin( $\frac { 1 } { 2 }$ sin?)
E) ? = arcsin( $\frac { 1 } { 2 }$ sin?)