Hello, gabriel!

Your description is quite confusing.

I'll take a guess at what the diagram looks like.

The area of the large square is: . square units.

The area of the small square is: . square units.

. . The area of the third square is: . square units.

Therefore, the side of the third square is units.

I would guess that the diagram looks like this:

Code:

5
A o - - - - - - - - - o B
|* |
| * |
| * |
| * |
| * | 3
5 | * G o - - - - o F
| * | * |
| P * | * |
| * |* | 3
| * * | R |
| * * Q | |
o - - - - - o - - - o - - - - o
D 3 P 2 C 3 E

and are hypotenuses of right triangles with legs 3 and 5.

Hence, theire lengths are: .

Move the pieces labeled to their new locations.

Code:

*
* |*
* | *
* | *
* | *
* | R | *
* Q | | *
A o--------*----------o *
.* | P *
. * | *
. * | *
. * | *
. * G o-----------o F
. * | * .
. * | * .
. * | * .
. * |* .
. * * . .
. * * . .
. . . . . . o . . . . . . . . . .
P