There are 5 shapes on a 9x9 grid. Which shape is closest to the pink 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: pink right_triangle at (4, 6)
Distance from target shape to brown square at (6, 6): 2
Distance from target shape to yellow trapezoid at (3, 1): 6
Distance from target shape to red right_triangle at (0, 3): 7
Distance from target shape to cyan trapezoid at (6, 3): 5
Closest shape is the brown square at (6, 6) with distance 2</think>

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