In radian measure, the angles of a 30-60-90 triangle are;

We know that
180 degrees is equal to pi radians
so
for 30 degrees
180°> pi radians
30°> x
x=30*pi/180> x=pi/6 radians

for 60 degrees
180°> pi radians
60°> x
x=60*pi/180> x=pi/3 radians

for 90 degrees
180°> pi radians
90°> x
x=90*pi/180> x=pi/2 radians

the answer is the option c
pi/6,pi/3,pi/2