There are 3 shapes on a 9x9 grid. Which shape is closest to the green rectangle 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 rectangle at (7, 5)
Distance from target shape to pink right_triangle at (6, 6): 2
Distance from target shape to purple square at (3, 8): 7
Closest shape is the pink right_triangle at (6, 6) with distance 2</think>

<answer>(6, 6)</answer>