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, 4)
Distance from target shape to red square at (4, 3): 2
Distance from target shape to orange right_triangle at (6, 6): 5
Closest shape is the red square at (4, 3) with distance 2</think>

<answer>(4, 3)</answer>