There are 3 shapes on a 9x9 grid. Which shape is closest to the green right_triangle 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 right_triangle at (4, 6)
Distance from target shape to brown right_triangle at (7, 7): 4
Distance from target shape to orange right_triangle at (7, 8): 5
Closest shape is the brown right_triangle at (7, 7) with distance 4</think>

<answer>(7, 7)</answer>