There are 4 shapes on a 10x10 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 (8, 4)
Distance from target shape to gray trapezoid at (6, 4): 2
Distance from target shape to blue square at (4, 5): 5
Distance from target shape to brown right_triangle at (4, 8): 8
Closest shape is the gray trapezoid at (6, 4) with distance 2</think>

<answer>(6, 4)</answer>