There are 5 shapes on a 8x8 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 (7, 6)
Distance from target shape to pink rectangle at (2, 0): 11
Distance from target shape to orange right_triangle at (3, 3): 7
Distance from target shape to brown square at (4, 4): 5
Distance from target shape to cyan right_triangle at (0, 3): 10
Closest shape is the brown square at (4, 4) with distance 5</think>

<answer>(4, 4)</answer>