There are 6 shapes on a 4x4 grid. Which shape is closest to the purple rectangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: purple rectangle at (3, 2)
Distance from target shape to gray right_triangle at (0, 0): 5
Distance from target shape to cyan square at (1, 1): 3
Distance from target shape to green right_triangle at (2, 2): 1
Distance from target shape to yellow right_triangle at (0, 1): 4
Distance from target shape to blue right_triangle at (1, 3): 3
Closest shape is the green right_triangle at (2, 2) with distance 1</think>

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