9514 1404 393
Answer:
C) 18
Explanation:
GD = GF + FE + ED
The lengths of GF and ED can be found from the relations ...
GF + FE = GE
GF + 1 = 12 . . . .use the given lengths
GF = 11 . . . . . . . subtract 1
and ...
FE + ED = FD
1 + ED = 7 . . . . use the given lengths
ED = 6 . . . . . . . subtract 1
Then the length of interest is ...
GD = GF + FE + ED
GD = 11 + 1 + 6
GD = 18