To determine the geometrical name of the figure formed by the points AA'BB', we can follow these steps:
### Step-by-Step Solution:
1. **Identify Points A and B**:
- Let's assume point A is (1, 2) and point B is (2, 3).
2. **Find Reflected Points A' and B'**:
- The reflection of point A (1, 2) across the x-axis gives us point A' (1, -2).
- The reflection of point B (2, 3) across the x-axis gives us point B' (2, -3).
3. **Plot Points on a Graph**:
- Plot the points A (1, 2), B (2, 3), A' (1, -2), and B' (2, -3) on a coordinate plane.
4. **Connect the Points**:
- Connect the points in the order: A to B, B to B', B' to A', and A' back to A.
5. **Analyze the Shape**:
- The figure formed by connecting these points is a closed shape.
- Since A and A' are vertically aligned and B and B' are also vertically aligned, and the lengths of AB and A'B' are equal (both are vertical lines), we can conclude that the figure is a trapezium.
6. **Determine the Type of Trapezium**:
- Since the lengths of the non-parallel sides (AB and A'B') are equal, the trapezium is classified as an isosceles trapezium.
### Final Answer:
The geometrical name of the figure AA'BB' is an **isosceles trapezium**.
