If you look at the figure, triangles XVW and ZYW are similar. So, you can use ratio and proportion to solve this problem. Notice that there are tick marks on th other two sides of the bigger triangles. That indicates that the like signs of ticks are equal. For example, that means XZ = ZW and that XW = 2XZ = 2ZW.
24.4/YZ = XW/ZW
24.4/YZ = 2ZW/ZW
24.4/YZ = 2
Solving for YZ,
YZ = 12.2
