The formula for the light bend would be n1*sin i= n2 * sin r
If you use "sin (90-x)= cos x" principle, you can change the sin in the equation into
n1*sin i= n2 * sin r
n1 * cos a= n2 * cos b
n2/n1= cos a/ cos b
Assuming the n constant is the ratio of the glass compared to water then the answer would be: cos a/ cos b
I don’t understand the language
Answer:

Step-by-step explanation:
A is the hyp. And b/c are the sides
A²=b²+c²=3²+2²=9+4=13
Now take the square root of 13 as the answer