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

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