There are 5 shapes on a 4x4 grid. Which shape is closest to the blue 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: blue right_triangle at (3, 2)
Distance from target shape to cyan right_triangle at (0, 3): 4
Distance from target shape to pink square at (2, 1): 2
Distance from target shape to brown right_triangle at (3, 3): 1
Distance from target shape to red right_triangle at (0, 2): 3
Closest shape is the brown right_triangle at (3, 3) with distance 1</think>

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