ZW and DA are similar sides
WX and AB are similar sides.
Make a proprtion of the sides.
[tex]\sf{ \frac{WX}{AB} = \frac{ZW}{DA} }[/tex]
Plug in the numbers
[tex]\sf{ \frac{6}{24} = \frac{ZW}{18} }[/tex]
Cross multiply
[tex]\sf{ 6\times 18=ZW \times 24[/tex]
And then solve for ZW
[tex]\sf{ZW = 4.5}[/tex]
So our final answer is
[tex]\boxed{\bf{4.5~centimeters}}[/tex]
Hope that helps :P
