finding the speed of light in a liquid - how do I find the refraction index and light speed? thx

[deleted-412478]

Hello -
I am doing a fair project using different liquids that affect the speed of light. I am not familiar with trigonometry; is there a simple explanation?

So I have set up my experiment with water and my laser coming in at 45 degrees. As I am measuring it, the refraction is 30 degrees, but I don't know if I am measuring it correctly.

If those measurements are correct, how would I find the refraction index and the speed of light? Thanks

[deleted-412478]

For measuring, you would place the protractor against the vertical plane, right?