There are 6 shapes on a 9x9 grid. Which shape is closest to the purple square 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 square at (7, 8)
Distance from target shape to brown right_triangle at (2, 5): 8
Distance from target shape to pink rectangle at (5, 2): 8
Distance from target shape to gray square at (4, 2): 9
Distance from target shape to orange right_triangle at (1, 8): 6
Distance from target shape to red trapezoid at (2, 2): 11
Closest shape is the orange right_triangle at (1, 8) with distance 6</think>

<answer>(1, 8)</answer>