I FOUND YOUR COMPLETE QUESTION IN OTHER SOURCES.
PLEASE SEE ATTACHED IMAGE.
For this case we have the following equation:
[tex] sin(40)=\frac{b}{20} [/tex]
From here, we clear the value of b which is the length of the AC segment.
We have then:
[tex] b=20*sin(40) [/tex]
Doing the calculations we have:
[tex] b = 12.85575219
[/tex]
Rounding for the nearest tenth we have:
[tex] b = 12.9
[/tex]
Answer:
The length of the segment AC is given by:
b = 12.9
