Line UVW is a straight line. This means it must have a measure of 180°. As you can see in the diagram, <UVX, <XVY, <YVZ, and <ZVW also split <UVW into four different angles. By this logic, we know:
<UVX + <XVY + <YVZ + <ZVW = 180°
Now, let's add in the values of the known angle measures and let x represent <YVZ in this equation:
