Final answer:
To calculate angle x, subtract 115 from 304, resulting in an angle size of 189 degrees.
Step-by-step explanation:
The question asks to work out the size of an angle denoted as x by subtracting 115 from 304. This operation falls under basic arithmetic within the broader subject of mathematics, specifically dealing with angle calculations.
To find the value of x, we simply perform subtraction:
x = 304 - 115
Therefore, x = 189.
The size of angle x is 189 degrees.