There are 6 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, 0)
Distance from target shape to red right_triangle at (0, 3): 6
Distance from target shape to cyan square at (1, 0): 2
Distance from target shape to yellow square at (0, 0): 3
Distance from target shape to orange square at (3, 1): 1
Distance from target shape to brown square at (3, 3): 3
Closest shape is the orange square at (3, 1) with distance 1</think>

<answer>(3, 1)</answer>