There are 3 shapes on a 6x6 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 (5, 5)
Distance from target shape to green trapezoid at (2, 5): 3
Distance from target shape to purple trapezoid at (1, 1): 8
Closest shape is the green trapezoid at (2, 5) with distance 3</think>

<answer>(2, 5)</answer>