There are 5 shapes on a 8x8 grid. Which shape is closest to the cyan 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: cyan right_triangle at (3, 7)
Distance from target shape to green rectangle at (4, 2): 6
Distance from target shape to purple rectangle at (3, 5): 2
Distance from target shape to yellow rectangle at (6, 7): 3
Distance from target shape to orange rectangle at (7, 5): 6
Closest shape is the purple rectangle at (3, 5) with distance 2</think>

<answer>(3, 5)</answer>