There are 4 shapes on a 6x6 grid. Which shape is closest to the orange 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: orange right_triangle at (5, 3)
Distance from target shape to red rectangle at (0, 5): 7
Distance from target shape to cyan right_triangle at (5, 1): 2
Distance from target shape to blue square at (5, 4): 1
Closest shape is the blue square at (5, 4) with distance 1</think>

<answer>(5, 4)</answer>