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 (0, 9)
Distance from target shape to cyan square at (2, 6): 5
Distance from target shape to pink rectangle at (6, 9): 6
Distance from target shape to yellow trapezoid at (3, 7): 5
Distance from target shape to purple right_triangle at (1, 8): 2
Distance from target shape to green trapezoid at (5, 6): 8
Closest shape is the purple right_triangle at (1, 8) with distance 2</think>

<answer>(1, 8)</answer>