There are 5 shapes on a 9x9 grid. Which shape is closest to the green 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: green right_triangle at (6, 8)
Distance from target shape to blue trapezoid at (5, 2): 7
Distance from target shape to yellow rectangle at (7, 1): 8
Distance from target shape to orange square at (6, 5): 3
Distance from target shape to purple right_triangle at (1, 2): 11
Closest shape is the orange square at (6, 5) with distance 3</think>

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