There are 2 shapes on a 6x6 grid. Which shape is closest to the green 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: green right_triangle at (4, 3)
Distance from target shape to orange right_triangle at (2, 1): 4
Closest shape is the orange right_triangle at (2, 1) with distance 4</think>

<answer>(2, 1)</answer>