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

<answer>(5, 6)</answer>