First draw a labelled diagram, like the one attached. This has altitudes addedOriginally Posted bySebastianasdf

to the two triangles, one with sides 13ft and 20ft and the other with sides

20ft and 17ft, and the square has side

(note in the diagram and )

Now apply Pythagoras's theorem to find from triangles

and , these give:

,

and

,

so:

Now doing the same thing for and triangles

and gives:

.

Also (as 20 is the diagonal of a rectangle with sides and ):

Now these three equations should be sufficient to solve tor

and from this the perimeter and area are easily found.

RonL