In the diagram below, and are parallel. Find
Triangles BCF and EDF are similar so y/20 = 9/10
You can take it from here.
and 
are parallel. Find 
![[asy] size(250);pair B = (0,0);pair C = (3,3);pair D = (5.5,2);pair E = (7.5,4);pair F = intersectionpoint(D--C, B--E);draw(D--E--F--cycle);draw(F--B--C--cycle);label(](/api/ssl-img-proxy?src=https%3A%2F%2Flatex.artofproblemsolving.com%2Fc%2F8%2F2%2Fc8262fe365222b9b6df5ffa85da4197a4886bc96.png)
