There are 3 shapes on a 4x4 grid. Which shape is closest to the blue 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: blue right_triangle at (1, 3)
Distance from target shape to cyan square at (2, 0): 4
Distance from target shape to brown rectangle at (3, 1): 4
Closest shape is the cyan square at (2, 0) with distance 4</think>

<answer>(2, 0)</answer>