Is it possible for brooke to draw a square and a rhombus that are congruent? why not?

No, it is not possible to draw a square and a rhombus that are congruent.

Explanation:
For any two shapes to be congruent:
1- Each side from the first shape must be equal to its corresponding side in the second shape
2- Each angle in the first shape must be equal to its corresponding angle in the second shape

Now, a rhombus is a quadrilateral whose four sides are equal, however, the angles are not right (each two opposite angles are equal but they are not right angles)
a square is defined as a rhombus whose 4 angles are 90 degrees.

So, while drawing a square and a rhombus, we can manage to draw sides of the square congruent to sides of the rhombus. However, the angles of the square can never be congruent to the angle of rhombus.
(If angles of rhombus turned into 90 degrees, then it would be converted to a square. And if angles of square turned to be each two opposite are equal nut not 90, it would be converted to a rhombus.)

Therefore, the second condition (condition of congruent angles) can never be achieved which means that a square and a rhombus can never be congruent.

Hope this helps :)