Answer :

AL2006
Question #85 is true.  It stands there and TELLS you how to convert from
degrees to radians. Right there, in Question #85, is everything you need to
know in order to do it.  Please don't make something hard out of something
easy.

Take Question #86 as an example:

The angle is 80 degrees.  According to the recipe in Question #85, you're
supposed to multiply 80 degrees by  (pi)/180.  Let's try it.  It won't bite.

(80) x (pi/180) = (pi) x (80/180) . 

Can you simplify the fraction  (80/180) ?  Divide the top and bottom by 20 ,
and you get  4/9 .

So the whole result is  4 pi / 9 .  Son of a gun !  That's the 3rd choice on the list !