There are 4 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 cyan right_triangle at (2, 5): 8
Distance from target shape to blue trapezoid at (3, 0): 2
Distance from target shape to red right_triangle at (2, 4): 7
Closest shape is the blue trapezoid at (3, 0) with distance 2</think>

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