Answer:
100
Step-by-step explanation:
It is a rule that for two opposite arcs, with intersecting lines, between them, the average of the arcs is equivalent to the inside angle. Given this, we can say that:
(CF + ED)/2 = angle G
plug values in
(12x+9x+10)/2 = 110
multiply both sides by 2
21x + 10 = 220
subtract 10 from both sides
21x = 210
divide both sides by 21
x=10
Plug this into DE
10*9+10 = 100
