Final answer:
Tangent circles inscribed in a square and tangent to each other form a smaller square within the larger square at the points of tangency.
Step-by-step explanation:
The question asks about the shape formed by tangent circles inscribed in a square. When circles are inscribed in a square and each circle is tangent to two sides of the square and to each other, they form a quadrilateral. To determine the shape, we need to consider the points of tangency.
If two circles are inscribed in a square and tangent to each other, the points of tangency to the square will define a smaller square within the larger one. The sides of the smaller square will be parallel to the sides of the larger square, and the points of tangency where the circles touch each other will be the corners of this smaller square. Hence, the correct answer is a square.