There are 4 shapes on a 9x9 grid. Which shape is closest to the green square 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 square at (6, 7)
Distance from target shape to cyan right_triangle at (8, 0): 9
Distance from target shape to blue square at (4, 3): 6
Distance from target shape to yellow square at (3, 8): 4
Closest shape is the yellow square at (3, 8) with distance 4</think>

<answer>(3, 8)</answer>