In figure, if the length of
¯¯¯¯¯¯¯¯BC equals one-half the length of
¯¯¯¯¯¯¯¯AB, the sum of
BC and
CD equals three-fourth the length of
¯¯¯¯¯¯¯¯¯AD, and the length of
¯¯¯¯¯¯¯¯¯AD equals
16, calculate the distance between point C and the midpoint of
¯¯¯¯¯¯¯¯¯AD.