Answer:
The critical angle is
![i = 41.84 ^o](https://img.qammunity.org/2021/formulas/physics/college/jr1sn12fkayqywdsozo3kseqvgubjizti3.png)
Step-by-step explanation:
From the question we are told that
The index of refraction of the sugar solution is
![n_s = 1.5](https://img.qammunity.org/2021/formulas/physics/college/gxrn3141zedinr6p8fkfyp7gox6cjemelr.png)
The index of refraction of air is
![n_a = 1](https://img.qammunity.org/2021/formulas/physics/college/1wn1qwlymiy5kvh1vp40pgjwnfabssciz8.png)
Generally from Snell's law
Note that the angle of incidence in this case is equal to the critical angle
Now for total internal reflection the angle of reflection is
![r = 90^o](https://img.qammunity.org/2021/formulas/physics/college/85efoop9l2hkw3p4ylvg5gxovgsv4puild.png)
So
![i = sin ^(-1) [( (sin (90)) * 1 )/(1.5) ]](https://img.qammunity.org/2021/formulas/physics/college/st01ypiy2w1e1ssydcou5ry3rqvn7b0ce8.png)
![i = 41.84 ^o](https://img.qammunity.org/2021/formulas/physics/college/jr1sn12fkayqywdsozo3kseqvgubjizti3.png)