There are 4 shapes on a 9x9 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 brown square at (5, 7): 2
Distance from target shape to yellow square at (5, 3): 2
Distance from target shape to purple trapezoid at (5, 8): 3
Closest shape is the brown square at (5, 7) with distance 2</think>

<answer>(5, 7)</answer>