There are 6 shapes on a 8x8 grid. Which shape is closest to the brown 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: brown right_triangle at (2, 7)
Distance from target shape to cyan rectangle at (5, 3): 7
Distance from target shape to green right_triangle at (6, 5): 6
Distance from target shape to blue trapezoid at (7, 6): 6
Distance from target shape to pink right_triangle at (3, 2): 6
Distance from target shape to gray trapezoid at (1, 1): 7
Closest shape is the green right_triangle at (6, 5) with distance 6</think>

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