There are 3 shapes on a 8x8 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, 5)
Distance from target shape to purple trapezoid at (4, 6): 3
Distance from target shape to pink trapezoid at (7, 5): 1
Closest shape is the pink trapezoid at (7, 5) with distance 1</think>

<answer>(7, 5)</answer>