Answer:
c = 89
Step-by-step explanation:
The sum of the exterior angles of a triangle = 360°
sum the 3 exterior angles and equate to 360
c + 65 + c + 28 + c = 360 , that is
3c + 93 = 360 ( subtract 93 from both sides )
3c = 267 ( divide both sides by 3 )
c = 89
