There are 2 shapes on a 7x7 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 (1, 5)
Distance from target shape to red square at (4, 0): 8
Closest shape is the red square at (4, 0) with distance 8</think>

<answer>(4, 0)</answer>