There are 3 shapes on a 7x7 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 orange rectangle at (6, 5): 6
Distance from target shape to red square at (1, 3): 7
Closest shape is the orange rectangle at (6, 5) with distance 6</think>

<answer>(6, 5)</answer>