There are 3 shapes on a 8x8 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 orange rectangle at (5, 1): 3
Distance from target shape to cyan rectangle at (1, 2): 4
Closest shape is the orange rectangle at (5, 1) with distance 3</think>

<answer>(5, 1)</answer>