There are 4 shapes on a 8x8 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 (1, 2)
Distance from target shape to green right_triangle at (5, 7): 9
Distance from target shape to blue square at (2, 1): 2
Distance from target shape to red right_triangle at (5, 6): 8
Closest shape is the blue square at (2, 1) with distance 2</think>

<answer>(2, 1)</answer>