Thread: proportions i think

I don't understand the attached problem. Can someone help me get this started?

Hello, igottaquestion!

135) A sloping ramp is to be built with vertical supports at as shown.

The supports at and are 11 and 17 ft, respectively.

How high must the supports be at point ?

Code:

                                       o -
                                    *  | :
                                 o     | :
                              *  |     | :
                           *     |     | :
                        o        |     | :
                     *  |        |     | 6
                  *     |        |     | :
               *        |        |     | :
            o           |        |     | :
         *  |           |        |     | :
      o     |           |        |     | -
      |     |           |        |     | :
      |     |           |        |     | :
      |     |           |        |     | :
   11 |     |           |        |     | 11
      |     |           |        |     | :
      |     |           |        |     | :
      |     |           |        |     | :
      o - - o - - - - - o - - - -o- - -o -
      A  12 B     30    C   18   D  12 E

   x  =    12          42       60    72

Placing at the origin,
. . the equation of the ramp is: .