There are 5 shapes on a 8x8 grid. Which shape is closest to the green rectangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: green rectangle at (4, 0)
Distance from target shape to red trapezoid at (0, 1): 5
Distance from target shape to brown trapezoid at (1, 2): 5
Distance from target shape to pink right_triangle at (3, 2): 3
Distance from target shape to cyan right_triangle at (5, 7): 8
Closest shape is the pink right_triangle at (3, 2) with distance 3</think>

<answer>(3, 2)</answer>