Final answer:
The fourth angle of the quadrilateral is 80 degrees.
Step-by-step explanation:
To find the fourth angle of a quadrilateral, we can use the fact that the sum of all four angles in a quadrilateral is always 360 degrees. In this case, the sum of three angles is given as 280 degrees. So, to find the fourth angle, we can subtract 280 from 360:
Fourth angle = 360 - 280 = 80 degrees
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