Help finding the length

[christofff]

Hi all,

Thanks for your time. I would like help in how to tackle finding the length of Y.

A, B, C and D will all be known values. If anyone is interested in the real life application of this problem, please feel free to ask, otherwise I wont bore you with it

Any and all help offered is appreciated.

 

[christofff]

Hi Denis, thank you for your prompt reply.

If I am understanding this right, the solution would be dependent on extending the lines into a right angle triangle (given as the first stage). On paper this would appear to me to be the best solution. In the real world application this would not be possible, as we do not know the angles except the two right angles.

The application is a cable between two structures and we want to know if the cable will be above a certain height at a particular point of the span.

May I ask you a question - given that it is possible to find the midline length of a right trapeziod by (a + b) x 0.5, would it be possible to find this length by...

1. working out the ratio of C to CD - in this case it is 0.35 of the way across.

2. multiplying that ratio by the sum of the two sides ie (a + b) x 0.3 ... would that give me the length of Y?