Answer:
50
Explanation:
bfa and afe will add up to equal 180 because they are supplementary
20x+2x+70=180
22x+70=180
22x=110
x=5
then you plug in 5 to 2x+70 to get 80
cfe and afe are also complementary so they will add up to equal 180 so angle cfe equals 100
cfd and cfe are the same angles so 100/2=50.
the arc length is the same as the angles so arc length dc is 50