If you remember that pi~3.142 all you got to do is substract the given number by this. That is,
arc(sin0.5)=~0.524=3.142-0.524= 2.618 rad
I have an exam coming up where you need to understand radians (which I do). But I would like to know if there is a good way to see what angles are expressed in fractions. I'll give an example.
In radians, arcsin(0,5)=~0,524. If you divide pi by this the answer is 6, so an accurate way is to answer arcsin(0,5)=pi/6.
But the angle could also be pi - pi/6. Is there a fast way of seeing what the fraction equal to this is?