There are 4 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 (4, 6)
Distance from target shape to yellow right_triangle at (6, 7): 3
Distance from target shape to brown right_triangle at (8, 9): 7
Distance from target shape to green rectangle at (2, 3): 5
Closest shape is the yellow right_triangle at (6, 7) with distance 3</think>

<answer>(6, 7)</answer>