There are 6 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 (1, 3)
Distance from target shape to blue rectangle at (3, 2): 3
Distance from target shape to purple square at (9, 9): 14
Distance from target shape to orange rectangle at (8, 4): 8
Distance from target shape to yellow square at (7, 7): 10
Distance from target shape to gray right_triangle at (3, 9): 8
Closest shape is the blue rectangle at (3, 2) with distance 3</think>

<answer>(3, 2)</answer>