There are 2 shapes on a 9x9 grid. Which shape is closest to the red 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: red square at (3, 8)
Distance from target shape to green right_triangle at (5, 4): 6
Closest shape is the green right_triangle at (5, 4) with distance 6</think>

<answer>(5, 4)</answer>