There are 6 shapes on a 9x9 grid. Which shape is closest to the orange 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: orange right_triangle at (1, 3)
Distance from target shape to pink square at (5, 1): 6
Distance from target shape to green right_triangle at (1, 0): 3
Distance from target shape to red rectangle at (3, 3): 2
Distance from target shape to yellow right_triangle at (2, 7): 5
Distance from target shape to gray right_triangle at (1, 1): 2
Closest shape is the red rectangle at (3, 3) with distance 2</think>

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