**From the case:**Refraction - Snell's law (diagram)

The diagram illustrates refraction angles based on Snell's Law and is an important concept in ultrasound.

Snell's law is as follows:

sin θ_{1}/c_{1} = sinθ_{2}/c_{2}

Where:

- θ
_{1}is the incident angle and θ_{2}is the refracted angle - c
_{1 }is the speed of propagation in the first material and c_{2}is the speed of propagation in the second material

Example of possible numerical values are shown in the diagram.