There are 3 shapes on a 5x5 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, 3)
Distance from target shape to brown square at (3, 2): 2
Distance from target shape to gray square at (2, 2): 3
Closest shape is the brown square at (3, 2) with distance 2</think>

<answer>(3, 2)</answer>