What is the length of Chord CD?

Question

 

Answer 1

9x-1 = 41x - 5

41x-9x = -1 + 5

32x = 4

x = 4/32 = 1/8

CD = 9x-1 = 9(1/8) - 1 = 9/8-1 = 1/8

this all assumes that CD = EF which looks reasonable visually. They appear to be the same length or very close.