There are 3 shapes on a 7x7 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 (3, 5)
Distance from target shape to cyan right_triangle at (2, 0): 6
Distance from target shape to green trapezoid at (6, 6): 4
Closest shape is the green trapezoid at (6, 6) with distance 4</think>

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