There are 3 shapes on a 9x9 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, 5)
Distance from target shape to red rectangle at (5, 0): 9
Distance from target shape to cyan right_triangle at (2, 1): 5
Closest shape is the cyan right_triangle at (2, 1) with distance 5</think>

<answer>(2, 1)</answer>