There are 4 shapes on a 10x10 grid. Which shape is closest to the purple 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: purple right_triangle at (8, 1)
Distance from target shape to pink rectangle at (7, 6): 6
Distance from target shape to orange trapezoid at (8, 4): 3
Distance from target shape to blue right_triangle at (6, 2): 3
Closest shape is the orange trapezoid at (8, 4) with distance 3</think>

<answer>(8, 4)</answer>