You can 
put this solution on YOUR website! 
How can you prove the converse of the diagonals of a rhombus are perpendicular.
The only converse that one could have would be this:
"If the diagonals of a parallelogram are perpendicular, the parallelogram is a rhombus." 
We would have to be given that it was a parallelogram.
Maybe you meant this instead:
The diagonals of a rhombus are perpendicular bisectors of each other.
Then the converse would be:
"If the diagonals of a quadrilateral are perpendicular bisectors of 
each other, the quadrilateral is a rhombus.
 Repost and tell us which one it is, or if it is smoething else.
Then we'll prove it.
Edwin
  
Repost and tell us which one it is, or if it is smoething else.
Then we'll prove it.
Edwin