1. ## Window

Maybe it's a logical problem, but it was proclaomed as a geometrical problem.
A window of a house was doubled, but its width and height didn't change. How it is possible?

2. maybe, this will sound funny but this is the only reason i can think of..

the length doubled.. see, it didn't ask you if it was its area, volume or whatsoever that doubled. and i haven't seen any window which is only two dimensional so maybe, that would be the answer..

3. My approach is logical and I'm sure there is a mathematical approach which isn't coming to my head.

I would say that as the width and height didn't change, it could mean that the window is split within (e.g. adding a frame in between). This would mean that there are two windows on either sides of the frame.

4. Thank you, Kalagota and Air!

Maybe, I found the solution, but I'm not sure:

The original window was a rhombus.

5. Hello, puco!

It's a trick question . . . and your answer is correct!

A window of a house was doubled, but its width and height didn't change.
How it is possible?

This is one possible shape for the window.

Code:
            *         -
*   *       :
*       *     :
*           *   :
*         *  height
*       *     :
*     *      :
*   *       :
* *        :
*         -
: - width - :

And the new window looks like this:

Code:
      *-----*-----*   -
|   .   .   |   :
| .       . |   :
*           *   :
|.         .| height
| .       . |   :
|  .     .  |   :
|   .   .   |   :
|    . .    |   :
*-----*-----*   -
: - width - :