There are 5 shapes on a 4x4 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 (0, 1)
Distance from target shape to yellow rectangle at (1, 3): 3
Distance from target shape to cyan rectangle at (2, 2): 3
Distance from target shape to purple rectangle at (3, 1): 3
Distance from target shape to green square at (1, 1): 1
Closest shape is the green square at (1, 1) with distance 1</think>

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