There are 3 shapes on a 9x9 grid. Which shape is closest to the yellow right_triangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: yellow right_triangle at (5, 5)
Distance from target shape to green right_triangle at (6, 7): 3
Distance from target shape to blue right_triangle at (6, 1): 5
Closest shape is the green right_triangle at (6, 7) with distance 3</think>

<answer>(6, 7)</answer>