Emaths trigo question ! Can someone help to solve Q20 in the attached file ? please explain to me how to get the answers provided, thank you ! ^^

Question

anonymous · Answer

attachment

anonymous · Answer

whats sin^-1(1/2)= ____radian?

anonymous · Answer

arc sin(1/2)= ____radian?

anonymous · Answer

sin x=1/2
then 
x=arc sin(1/2)=___radian?

anonymous · Answer

i can only get the ans 0.524 but cant get the other answer :(

anonymous · Answer

ok lets try to do this  like this

whats 0.524 rad in degrees?

anonymous · Answer

31.054° ?

anonymous · Answer

its 30 degrees correct?
then to find the other theta in degrees would be
180 deg - 30deg = a50 deg=___rad?

anonymous · Answer

2.62 ° ! omg thank you so much ! ^^

anonymous · Answer

so the diagram is actually useless right ? >< only the bottom statement is needed to solve

anonymous · Answer

yup it looks like the 2.3 is an arc