There are 5 shapes on a 9x9 grid. Which shape is closest to the gray 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: gray right_triangle at (1, 8)
Distance from target shape to brown rectangle at (7, 7): 7
Distance from target shape to cyan right_triangle at (4, 3): 8
Distance from target shape to green trapezoid at (8, 7): 8
Distance from target shape to blue right_triangle at (0, 4): 5
Closest shape is the blue right_triangle at (0, 4) with distance 5</think>

<answer>(0, 4)</answer>