There are 3 shapes on a 9x9 grid. Which shape is closest to the red 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: red right_triangle at (2, 1)
Distance from target shape to yellow rectangle at (5, 0): 4
Distance from target shape to purple rectangle at (7, 4): 8
Closest shape is the yellow rectangle at (5, 0) with distance 4</think>

<answer>(5, 0)</answer>