There are 6 shapes on a 8x8 grid. Which shape is closest to the yellow rectangle in terms of Manhattan distance? The final answer is the grid position of the closest shape like (row_index, column_index).
<think>Target shape: yellow rectangle at (4, 5)
Distance from target shape to blue right_triangle at (2, 2): 5
Distance from target shape to gray rectangle at (1, 3): 5
Distance from target shape to brown rectangle at (1, 4): 4
Distance from target shape to cyan right_triangle at (6, 5): 2
Distance from target shape to orange square at (5, 3): 3
Closest shape is the cyan right_triangle at (6, 5) with distance 2</think>

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