There are 3 shapes on a 10x10 grid. Which shape is closest to the red 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: red right_triangle at (5, 4)
Distance from target shape to orange rectangle at (6, 3): 2
Distance from target shape to blue right_triangle at (7, 5): 3
Closest shape is the orange rectangle at (6, 3) with distance 2</think>

<answer>(6, 3)</answer>