As two angles are give as , 1/2 and 1/3 radian so ,
1/2 radian=1/2×180/π degree =28.66 degree
1/3 radian=1/3×180/π degree =19.10 degree
Now as we know that sum of all the angle can be give as, 28.66+19.10+x=180 (let third angle be x)x= 132.23 degree
Now converting it into the radian we get, x=132.23×π/180=2.30 radian