There are 4 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, 0)
Distance from target shape to orange right_triangle at (2, 5): 7
Distance from target shape to yellow rectangle at (3, 0): 1
Distance from target shape to cyan right_triangle at (5, 4): 5
Closest shape is the yellow rectangle at (3, 0) with distance 1</think>

<answer>(3, 0)</answer>