There are 3 shapes on a 10x10 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 (6, 9)
Distance from target shape to blue right_triangle at (5, 1): 9
Distance from target shape to gray square at (3, 6): 6
Closest shape is the gray square at (3, 6) with distance 6</think>

<answer>(3, 6)</answer>