There are 4 shapes on a 6x6 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 (2, 5)
Distance from target shape to orange right_triangle at (3, 1): 5
Distance from target shape to brown right_triangle at (1, 0): 6
Distance from target shape to purple square at (2, 4): 1
Closest shape is the purple square at (2, 4) with distance 1</think>

<answer>(2, 4)</answer>