I need to find AB.
By a geometric theorem (involving similar triangles): CB · CA = CD · CL
---> (7) · (7 + 2x + 3) = (9) · (9 + x + 1)
---> (7) · (10 + 2x) = (9) · (10 + x)
---> 70 + 14x = 90 + 9x
...
find x; then find AB ...
