There are 5 shapes on a 4x4 grid. Which shape is closest to the pink 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: pink right_triangle at (2, 1)
Distance from target shape to purple trapezoid at (2, 2): 1
Distance from target shape to blue square at (1, 3): 3
Distance from target shape to green trapezoid at (3, 1): 1
Distance from target shape to cyan square at (0, 0): 3
Closest shape is the purple trapezoid at (2, 2) with distance 1</think>

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