There are 4 shapes on a 3x3 grid. Which shape is closest to the green square in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: green square at (1, 2)
Distance from target shape to blue right_triangle at (1, 0): 2
Distance from target shape to orange right_triangle at (0, 0): 3
Distance from target shape to purple right_triangle at (2, 1): 2
Closest shape is the blue right_triangle at (1, 0) with distance 2</think>

<answer>(1, 0)</answer>