Answer:
x = 76
Step-by-step explanation:
All angles must add up to 360 degrees. So, we add the angles we already have.
104 + 123 + 57 + x= 360 we will solve for x
284 + x = 360 add all known values on the left
x = 76 we subtract 284 from both sides to isolate x
To check our answer, we add all values
104 + 123 + 57 + (76) = 360 This is correct. :)
