To solve the given figure matrix problem, we need to identify the pattern or rule governing the arrangement of shapes within the matrix. Let's analyze the given 3x3 matrix:

We observe that each row and column has a specific characteristic pattern in terms of the arrangement of shapes within a circle or square:

1. First Row:
   • Circle with triangle inside
   • Triangle with square inside
   • Square with circle inside
2. Second Row:
   • Triangle with square inside
   • Square with dot inside
   • Circle with triangle inside
3. Third Row:
   • Square with circle inside
   • Circle with triangle inside
   • Missing Element

By examining the pattern, we observe that the shapes in each row are arranged such that they form a sequence or rotation of enclosing one another (i.e., Circle → Triangle → Square → Circle → ..., and so on).

For the third row, the sequence appears to repeat in the order: Square → Circle → Triangle → ..., based on the elements present in other rows.

Thus, the missing element in the bottom right should be a triangle with a square inside, following the same sequence pattern.

Conclusion: The correct answer is the third option with a triangle enclosing a square.