Need help with math question points and brainlest

Answer:
Since the quadrilaterals ABCD and FGHJ are similar,
[tex]\frac{AD}{FG} = \frac{CD}{FJ} \\or, \frac{14}{x} = \frac{12}{18}\\or, x = \frac{14(18)}{12} = 21[/tex]ft