There are 6 shapes on a 10x10 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 (6, 4)
Distance from target shape to green trapezoid at (0, 1): 9
Distance from target shape to purple square at (2, 6): 6
Distance from target shape to pink square at (7, 9): 6
Distance from target shape to orange square at (3, 1): 6
Distance from target shape to brown rectangle at (5, 8): 5
Closest shape is the brown rectangle at (5, 8) with distance 5</think>

<answer>(5, 8)</answer>