There are 4 shapes on a 10x10 grid. Which shape is closest to the blue 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: blue right_triangle at (2, 3)
Distance from target shape to brown right_triangle at (1, 5): 3
Distance from target shape to gray rectangle at (6, 4): 5
Distance from target shape to yellow rectangle at (7, 6): 8
Closest shape is the brown right_triangle at (1, 5) with distance 3</think>

<answer>(1, 5)</answer>