90 degress= ? radians

Question

How is the answer pie over 2?
330 degrees = 11pie over 6
-105 degrees= -7pie over 12

Converting the angle in radians to degrees
3pie over 4 =135 degrees
pie over 2 = 90 degrees

pie over 30 = 6 degrees

-7pie over 5 =-135 degrees

I have these answers but I have no idea on how to get them..

Answer 1

Since 360 degrees = 2 pi radians BY DEFINITION, 90 degrees must be pi/2 radians.It is 1/4 of a complete circle.

All of your questions are worked the same way.

pi/30 radians = [pi/30]* [360 deg/(2 pi rad)]
= 6 degrees