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 (0, 5)
Distance from target shape to green square at (2, 7): 4
Distance from target shape to cyan right_triangle at (1, 7): 3
Distance from target shape to pink trapezoid at (7, 7): 9
Distance from target shape to gray rectangle at (1, 5): 1
Distance from target shape to red trapezoid at (7, 5): 7
Closest shape is the gray rectangle at (1, 5) with distance 1</think>

<answer>(1, 5)</answer>