There are 3 shapes on a 9x9 grid. Which shape is closest to the purple trapezoid 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 trapezoid at (8, 8)
Distance from target shape to green right_triangle at (1, 6): 9
Distance from target shape to gray trapezoid at (6, 0): 10
Closest shape is the green right_triangle at (1, 6) with distance 9</think>

<answer>(1, 6)</answer>