There are 5 shapes on a 6x6 grid. Which shape is closest to the purple 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: purple right_triangle at (5, 0)
Distance from target shape to yellow square at (3, 0): 2
Distance from target shape to green rectangle at (0, 1): 6
Distance from target shape to red square at (1, 4): 8
Distance from target shape to blue right_triangle at (2, 3): 6
Closest shape is the yellow square at (3, 0) with distance 2</think>

<answer>(3, 0)</answer>