There are 4 shapes on a 7x7 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 (5, 6)
Distance from target shape to pink trapezoid at (3, 0): 8
Distance from target shape to gray square at (2, 5): 4
Distance from target shape to red right_triangle at (2, 6): 3
Closest shape is the red right_triangle at (2, 6) with distance 3</think>

<answer>(2, 6)</answer>