There are 6 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, 4)
Distance from target shape to brown rectangle at (4, 7): 6
Distance from target shape to yellow rectangle at (2, 1): 4
Distance from target shape to pink rectangle at (4, 4): 3
Distance from target shape to blue trapezoid at (5, 5): 5
Distance from target shape to cyan right_triangle at (1, 6): 2
Closest shape is the cyan right_triangle at (1, 6) with distance 2</think>

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